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This Campbell's string bean casserole recipe delivers the nostalgic comfort of a classic one-pot meal with cheesy layers and crispy golden edges. đ I first made this in my cramped Boston apartment kitchen after a particularly tough week, and it became my go-to for quick, satisfying dinners that felt like a hug in a dish.
The secret lies in layering the creamy soup base with tender green beans and melted cheese, then baking until bubbly and golden.
The beauty of this recipe is its simplicityâjust a handful of ingredients come together in one pot, yet the result is restaurant-quality comfort food. Campbell's cream of mushroom soup forms the creamy foundation, while canned green beans add freshness and texture.
The cheese topping browns beautifully, creating that satisfying crunch we all love, while the layers ensure every bite is packed with flavor.
What you'll end up with is a creamy, cheesy casserole that's tender, rich, and perfectly golden on topâa dish that's equal parts comforting and impressive. The aroma alone will have everyone gathering around the table, and the texture delivers on that perfect balance of creamy, crunchy, and tender.
This is the kind of meal that tastes even better the next day, making it ideal for meal prep or feeding a crowd.
Ready to make this classic casserole? The instructions are straightforward, and the results are guaranteed to satisfy. Let's get started with this timeless comfort dish that brings back memories of home-cooked meals.
Ingredients for campbell's string bean casserole
Fourteen simple ingredients transform into nostalgic comfort in one pot.
| Ingredient | Amount | Notes |
|---|---|---|
| Campbell's Cream of Mushroom Soup đ | 2 cans | Condensed, 10.5 oz each |
| String Beans đ± | 2 cans | Drained, 14.5 oz each |
| Milk đ„ | 1 cup | Whole for creaminess |
| Butter đ§ | Âœ cup | Unsalted, melted |
| All-Purpose Flour đŸ | ÂŒ cup | For thickening |
| Sharp Cheddar Cheese đ§ | 2 cups | Shredded, fresh |
| Processed American Cheese đ§ | 1 cup | Shredded, for browning |
| Salt đ§ | Âœ tsp | Kosher or sea salt |
| Ground Black Pepper đ¶ïž | ÂŒ tsp | Freshly ground |
| Garlic Powder đ§ | Âœ tsp | For subtle depth |
| Onion Powder đ§ | Âœ tsp | Enhances flavor |
| Panko Breadcrumbs đ | ÂŒ cup | For extra crunch |
| Olive Oil đ« | 1 tbsp | For greasing dish |
The Campbell's cream of mushroom soup is the heart of this dishâgrab the condensed cans (not the ready-to-serve kind) from any grocery store. I always check the expiration date on the can, because that creamy base is what makes this casserole sing. For the string beans, Green Giant or Del Monte are my go-tosâthey drain well and hold their texture. The cheese matters too: sharp cheddar for flavor and American cheese for that perfect golden-brown crust. I buy my cheeses in blocks and shred them myselfâpre-shredded gets clumpy and doesn't melt as nicely. The butter should be unsalted, and if you're in a hurry, melt it in the microwave for 40 seconds instead of on the stove.
No Campbell's soup? Homemade mushroom sauce worksâjust blend cooked mushrooms, milk, and a splash of cream with some flour. Running low on string beans? Green beans or asparagus are great swaps, though they might need a minute less baking. Fresh herbs like parsley or thyme can replace the powders if you've got themâjust use half the amount. For the breadcrumbs, regular panko or crushed saltines work in a pinch. If you're watching calories, you can reduce the butter by a tablespoon and use a little more milk to compensate. The key is keeping that creamy texture balanced with the crispy topâdon't skip the breadcrumbs, even if you're short on time.
This casserole reheats beautifullyâhonestly tastes better the next day once everything melts together. Store leftovers in an airtight container for 4-5 days in the fridge. For freezing, portion it into individual servings before baking, then freeze for up to 3 months. When reheating, cover with foil and warm in the oven at 350°F for 20-25 minutes. I always make a double batchâone for dinner, one for lunches the next week. The flavors only get richer as it sits, so it's perfect for meal prep.
Why You'll Love This Recipe
- One-Pot Magic: I swear by this recipe when I need zero cleanup. Just toss the string beans, soup, and milk into a buttered pan, sprinkle flour on top, and bake. No chopping, no fussâjust pure, creamy satisfaction.
- Creamy Mushroom Hug: That Campbellâs soup brings deep, savory flavor without extra effort. The string beans soak it up like a sponge, giving you that rich, velvety texture with just a hint of earthinessâno fancy ingredients needed.
- Leftover Goldmine: This casserole actually tastes better the next day. I make a big batch on Sundays, and by Wednesday, itâs the star of my lunchbox. Reheats perfectly, so itâs my go-to for busy weeks.
- Budget-Friendly Feast: For under $5, I feed my family four hearty servings. String beans are cheap, the soupâs a pantry staple, and the flour-butter roux stretch it into something restaurant-worthy. (Yes, even on a Tuesday night.)
Step-by-step instructions for Campbell's string beans casserole
This one-pot wonder delivers that perfect cheesy, creamy, crunchy combo everyone loves.
đł Step 1: Make the Creamy Sauce Base
In a large oven-safe skillet, melt the 0.5 cup butter over medium heat. Once melted and foaming, whisk in the 0.25 cup all-purpose flour and cook for 1-2 minutes until golden brown. This creates a roux that will thicken your sauce beautifully.
Slowly pour in the 1 cup milk while whisking constantly to prevent lumps. Let the mixture simmer for 3-4 minutes until it thickens enough to coat the back of a spoon. You're building the creamy foundation that makes this casserole so satisfyingâdon't rush this step or it'll end up grainy.
đšâđł Step 2: Add the Soups and Seasonings
Stir in the 2 cans Campbell's Cream of Mushroom Soup and 2 cans drained string beans. The beans will soften slightly as they absorb the warm sauce. Sprinkle in the 0.5 tsp salt, 0.25 tsp ground black pepper, 0.5 tsp garlic powder, and 0.5 tsp onion powderâthese seasonings will infuse the entire dish with savory depth.
Gently fold everything together until well combined. You'll see the mixture thicken further as the heat activates all the ingredients. This is where the magic happensâthe flavors meld together into that comforting, cheesy bean casserole we all know and love. Taste and adjust seasoning if needed.
đ„ Step 3: Layer the Cheeses
Reduce heat to low and sprinkle half of the 2 cups sharp cheddar cheese and all of the 1 cup processed American cheese evenly over the top. The processed cheese adds that perfect melty, stretchy quality that makes this casserole so irresistible. Let it sit for 2 minutes to begin melting slightly into the sauce below.
Here's the thingâdon't skip this layering step. The cheddar on top gives you that classic cheesy flavor, while the American cheese in the middle creates that gooey, pull-apart texture. It's what makes this casserole feel so indulgent while still being simple to prepare.
đ„ Step 4: Bake to Golden Perfection
Preheat your oven to 375°F. Transfer the skillet to the oven and bake for 15 minutes. Watch closely after 12 minutes
Remove from the oven and sprinkle the remaining 1 cup sharp cheddar cheese and 0.25 cup panko breadcrumbs evenly over the top. Return to the oven for another 5-7 minutes until the breadcrumbs are golden brown and the cheese is fully melted and bubbly. That crispy topping is what makes this casserole feel like a restaurant-quality dish. Let the casserole rest for 5 minutes before serving. This gives the cheeses time to set slightly and makes it easier to scoop out perfect portions. The breadcrumbs will be crispy on top while the interior remains creamy and cheesyâexactly what you want in a comforting casserole. Serve immediately with crusty bread or over a side salad. The contrast of the warm, cheesy casserole with cool greens makes this dish feel like a complete meal. Leftovers keep well in the refrigerator for 3-4 days, though I doubt you'll have any left!â° Step 5: Rest and Serve Warm
Pro Tips For Making Campbell'S String Bean Casserole
- Prep Beans Right: Trim the ends of your string beans and snap them in halfâthis saves time and keeps them from curling up in the casserole. (Yes, even if youâre impatient like me, take the 2 minutes to do this properly.)
- Donât Boil the Soup: Campbellâs Cream of Mushroom is already thick, and boiling it will make the sauce break. Heat it on medium-low until just warm enough to melt the butterâabout 3 minutes. (I learned this the hard way when my first batch turned grainy.)
- Use Cold Milk: Stir the cold milk into the soup last, right before adding it to the beans. This keeps the sauce from curdling and gives you a smoother, creamier texture. (Sounds weird, but it worksâtrust me.)
- Toast the Flour: Melt the butter in the skillet first, then whisk in the flour and cook for 30 seconds until itâs golden. This makes the roux richer and cuts through the canned soupâs artificial taste. (I skip this when Iâm lazy, but the dish is noticeably better when I donât.)
Common mistakes when making this dish
Skipping the Roux
Iâve seen this happen more times than I can countâsomeone skips making the roux with butter and flour, thinking the Campbellâs soup will thicken everything enough. Hereâs the deal: that creamy sauce needs that roux to properly thicken and bind all the ingredients together.
Without it, your casserole will end up watery and sad. Trust me, those 1-2 minutes of stirring are worth it for that velvety texture. đ
Overmixing the Cheese
This is a classic rookie move: stirring the cheese into the sauce before baking. The moment you mix that cheese in, you lose the beautiful layers of melted cheddar and gooey American that make this dish special.
Sprinkle it on top and let it melt into that golden blanketâdonât ruin the surprise! Iâve even seen people add the breadcrumbs to the sauce before baking, which kills the crispy topping. Save the mixing for after baking.
Underbaking or Overbaking
This oneâs tricky because ovens vary, but Iâve had people pull their casserole out too soon (result: soupy cheese) or leave it in too long (result: burnt breadcrumbs and dry beans). Aim for that 5-7 minutes with the breadcrumbsâwatch for golden brown, not black.
If your oven runs hot, tent it with foil halfway through. And for the love of comfort food, donât peek too often! Every time you open that oven door, youâre letting heat escape and extending bake time.
Using Pre-Shredded Cheese
Listen, I get itâpre-shredded cheese is convenient. But itâs packed with anti-caking agents that prevent it from melting smoothly. The result? Gritty, clumpy cheese instead of that silky, stretchy goodness.
If youâre using pre-shredded, at least buy the block cheese and shred it yourselfâitâs worth the extra 5 minutes of work. I promise your casserole will thank you with that perfect melt. đ§
Ignoring the Resting Time
I know, I knowâyouâre starving and that casserole looks perfect. But skipping the 5-minute rest means youâll end up with a messy, runny pile when you try to serve it. That resting time lets the cheeses set just enough to hold their shape while keeping the interior creamy.
Itâs like letting your coffee sit before drinkingâpatience pays off. Trust the process, even if it feels like an eternity when youâre hungry.
Not Greasing the Dish Properly
This might seem like a no-brainer, but Iâve seen people skip this step or only grease the bottom. That casserole needs to release cleanly from the pan, especially if youâre using a non-stick skillet.
Brush that 1 tablespoon olive oil all over the insideâbottom, sides, even the top if youâre ambitious. A little effort here means no scrubbing later. And if youâre using a glass dish, make sure itâs oven-safeâsome glassware canât handle the heat and might shatter.
Nutrition facts
Frequently asked questions about string bean casseroles
Can I make this casserole without Campbell's soup?
For a homemade version, blend 1 cup cooked mushrooms, 1 cup milk, 2 tbsp butter, and 2 tbsp flour until smooth. Simmer for 5 minutes to thicken, then proceed with the recipe. The texture will be slightly different but equally delicious.
How do I prevent the breadcrumbs from getting soggy?
Always add breadcrumbs after the initial baking phase, not before. The key is baking the cheese layer first for 15 minutes, then topping with breadcrumbs and baking another 5-7 minutes. For extra crunch, broil for 1-2 minutes at the very endâjust watch closely to avoid burning.
What's the best way to reheat leftovers?
Cover with foil and warm in a 350°F oven for 15-20 minutes until bubbly. Microwaving works tooâjust add 1 tbsp milk to prevent drying. The flavors actually improve overnight, making leftovers taste even better!
Can I use frozen green beans instead of canned?
Yes, but thaw and drain them first. For 2 cups frozen beans, boil for 3 minutes until tender, then drain well before mixing with the soup. They'll release more moisture, so you might need an extra 5 minutes of baking time to firm up the casserole.
What makes this casserole different from other bean casseroles?
The secret lies in the layered cheeses and the roux-thickened sauce. Unlike creamy versions that use evaporated milk, this recipe builds flavor through the butter-flour roux and the cheddar-American cheese combo. The panko topping adds texture most recipes skip, creating that perfect crunchy-cheesy contrast.