You know that moment when the table goes quiet because everyone is taking that first bite? This is that casserole. Creamy mushrooms, tender green beans, a little smoky bacon, and a golden shower of crispy fried onions. It is cozy, celebratory, and wildly simple.
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I tested this Ultimate Green Bean Casserole several times to get the texture just right: silky sauce that clings to the beans, edges that bubble, and a topping that stays crisp. It's the classic you want on your holiday table, but easy enough for Sunday dinner. Ready to make it together? Let's get cooking.
Why You'll Love This Recipe
- Creamy, savory sauce with real mushrooms and garlic for depth.
- Pantry-friendly: canned green beans and cream of mushroom soup keep it fuss-free.
- Family-approved flavors with bacon and Monterey Jack for gentle richness.
- Easy dinner side that pairs with turkey, roast chicken, or weeknight meatloaf.
- Bakes in one 9x13 pan and can be prepped ahead for busy days.
Ingredients
- 6 strips bacon
- ½ yellow onion, finely diced
- 1 ½ cups chopped button mushrooms
- 3 cloves garlic, minced
- 2 cans (10.5 ounces each) cream of mushroom soup, undiluted
- ¼ cup milk
- 1 cup shredded Monterey Jack cheese
- Kosher salt and freshly ground black pepper, to taste
- 4 cans (14.5 ounces each) cut green beans, drained
- 1 ½ cups French fried onions
Ingredient Notes & Substitutions
- Bacon: Turkey bacon works if you want a lighter option. Prefer vegetarian? Skip the bacon and start with 2 tablespoons butter or olive oil.
- Mushrooms: Button mushrooms are mild, but cremini add an earthy note. Slice them a touch thicker so they brown, not steam.
- Cream of mushroom: Use your favorite condensed brand. Want to reduce sodium? Choose a low-sodium version and season at the end.
- Milk: Whole milk gives a silkier finish, but 2% works. For dairy-free, try unsweetened almond milk and swap the cheese for a melty dairy-free option.
- Cheese: Monterey Jack melts smoothly and stays mild. Sharp cheddar brings a little tang if you'd like more bite.
- Green beans: Canned keeps this classic weeknight-friendly. If you prefer fresh, blanch trimmed green beans in salted boiling water for 4 minutes, chill in ice water, and dry well before folding into the sauce.
- Fried onions: These are the signature crunch. Gluten-free versions are widely available now.

Instructions
- Heat the oven: Preheat to 350°F. Lightly spray a 9x13-inch baking dish with nonstick cooking spray.
- Cook the bacon: In a large skillet over medium low heat, cook bacon until crisp. Transfer to a paper towel-lined plate and crumble when cool.
- Sauté the aromatics: Drain all but about 2 tablespoons of the bacon drippings. Return the skillet to medium heat. Add onion and cook, stirring occasionally, until translucent, about 5 minutes.
- Brown the mushrooms: Add mushrooms and cook 5 minutes, stirring occasionally, until golden with little browned edges. Stir in garlic and cook 1 minute until fragrant.
- Build the sauce: Stir in both cans of undiluted cream of mushroom soup. Add the crumbled bacon back to the pan and stir to combine. Pour in the milk and add the Monterey Jack. Stir until the cheese melts and the sauce looks smooth and glossy. Season with salt and pepper to taste.
- Fold in the beans: Add the drained green beans and gently fold until they're well coated.
- Assemble and bake: Pour the mixture into the prepared baking dish. Scatter the French fried onions evenly over the top. Bake, uncovered, for 30 minutes, until hot and bubbly around the edges and the onions are deeply golden.
- Serve: Let it rest 5 minutes so the sauce settles, then scoop generous portions. The topping stays crisp and the sauce turns silky as it cools slightly.
Cook's cue: If your mushrooms aren't browning, give them space in the pan. A crowded skillet traps steam and keeps them pale.
Pro Tips for Success
Top Tip
- Golden mushrooms = flavor: Let mushrooms sit undisturbed for 1 to 2 minutes per side so they caramelize.
- Taste before salting: Condensed soup, bacon, and fried onions all bring salt. Season after the cheese melts and beans are folded in.
- Keep the topping crisp: Bake uncovered and avoid over-stirring once the fried onions are on.
- Right bakeware: A metal 9x13 heats a bit faster than ceramic. If using heavy ceramic, add 5 minutes if the center isn't bubbling yet.
- Fresh bean option: Blanch, shock, and dry fresh beans thoroughly to keep the sauce from thinning.
Storage and Reheating
- Store: Cover and refrigerate up to 3 days.
- Reheat: Warm in a 350°F oven, uncovered, 15 to 20 minutes. If the topping needs a refresh, add a small handful of fried onions in the last 5 minutes.
- Freeze: Assemble without the onion topping, wrap tightly, and freeze up to 2 months. Thaw overnight, top with onions, and bake as directed.
Make Ahead & Freezing
- Make ahead: Assemble the casserole up to the topping, cover, and refrigerate 24 hours. Add fried onions just before baking.
- Freezer plan: Freeze the sauce-and-beans base in the baking dish. On the day of, thaw, top, and bake. This keeps the onions crisp.
Tips and Variations
- Lighter version: Skip bacon and use low-sodium soup, then swap ½ cup of the fried onions for ½ cup toasted panko mixed with a teaspoon of olive oil.
- Extra mushroom: Double the mushrooms and sauté until deeply brown for a more savory bite.
- Cheese twist: Try half Monterey Jack and half sharp cheddar for a little tang.
- Spice it up: Add a pinch of cayenne or a dash of hot sauce to the sauce for gentle heat.
- Fresh herb finish: Sprinkle with chopped parsley or thyme just before serving for color and aroma.
- Gluten-free: Use gluten-free fried onions and verify your soup is certified gluten-free.

FAQs
Yes. Blanch for 4 minutes in salted water, shock in ice, dry very well, then proceed. This keeps them crisp-tender and prevents a watery sauce.
Reheat uncovered so steam escapes. If needed, add a small sprinkle of fresh fried onions in the last 5 minutes.
Make it one day ahead for best texture. Longer than 24 hours and the onions soften. Add the topping just before baking.
Whisk in an extra tablespoon or two of milk until it loosens slightly. It should coat a spoon and slowly slide off.
Absolutely. Skip the bacon, start with butter or oil, and season with a little smoked paprika for a hint of smokiness.
📖 Recipe

Ultimate Green Bean Casserole
- Prep Time: 20 minutes
- Cook Time: 30 minutes
- Total Time: 50 minutes
- Yield: 10 servings 1x
- Category: Side dish
- Method: Baking
- Cuisine: American
Description
Creamy mushrooms, tender green beans, smoky bacon, and a golden layer of crispy onions this is the ultimate green bean casserole for any celebration.
Ingredients
- 6 strips bacon
- ½ yellow onion, finely diced
- 1 ½ cups chopped button mushrooms
- 3 cloves garlic, minced
- 2 cans (10.5 ounces each) cream of mushroom soup, undiluted
- ¼ cup milk
- 1 cup shredded Monterey Jack cheese
- Kosher salt and freshly ground black pepper, to taste
- 4 cans (14.5 ounces each) cut green beans, drained
- 1 ½ cups French fried onions
Instructions
- Preheat the oven to 350°F and lightly spray a 9x13-inch baking dish.
- Cook bacon in a large skillet over medium low heat until crisp. Drain on paper towels; crumble.
- Pour off all but 2 tablespoons of drippings. Sauté onion over medium heat until translucent, about 5 minutes.
- Add mushrooms and cook 5 minutes until browned. Stir in garlic; cook 1 minute.
- Stir in undiluted soup, return bacon to the pan, then add milk and cheese. Stir until melted and smooth. Season to taste.
- Fold in green beans. Transfer to the prepared dish.
- Top with fried onions and bake, uncovered, 30 minutes until hot and bubbly. Rest 5 minutes before serving.
Notes
Store covered in the fridge up to 3 days. Reheat in a 350°F oven, uncovered, for 15-20 minutes. To freeze, assemble without topping, wrap tightly, and bake from thawed with onions added on top.
Nutrition
- Serving Size: 1 cup
- Calories: 265
- Sugar: 4g
- Sodium: 780mg
- Fat: 16g
- Saturated Fat: 6g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 20g
- Fiber: 2g
- Protein: 10g
- Cholesterol: 25mg
Serving Suggestions
This casserole loves the holiday table alongside roast turkey, maple glazed carrots, and fluffy mashed potatoes. On a regular weeknight, pair it with roasted chicken thighs or pan-seared pork chops. For a cozy plate, add a bright green salad with lemon vinaigrette to balance the richness.


Nutrition & Notes
- Yield: 10 servings
- Serving size: About 1 cup
- Approximate nutrition per serving: 265 calories, 16g fat, 20g carbohydrates, 10g protein, 2g fiber, 780mg sodium
- Category: Side dish
- Cuisine: American comfort
- Author: Lily, Let's Fly Tasty
- Tested notes: I've made this version many times to dial in the sauce thickness and topping ratio. The key is browning the mushrooms and tasting for seasoning only after the cheese melts.
Related Recipes / Internal Link
You may also like my Creamy Mushroom Risotto for another comforting, mushroom-forward side that steals the show.
External Resource
For more on sautéing mushrooms for deep flavor, this Serious Eats guide is helpful and thorough.






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