Green pea casserole is a creamy, cheesy side dish made with tender peas, mushrooms, cheddar cheese, and a simple homemade cream sauce. Finished with crispy French fried onions, it has the cozy flavor of a classic holiday casserole with a fresh twist. This easy green pea casserole is perfect for Thanksgiving, Easter, potlucks, Sunday dinners, or any meal that needs a comforting vegetable side. It takes about 45 minutes from start to finish, with only 10 minutes of prep, and serves 8 people.
Green bean casserole is a well-loved dish in many homes, especially during the holidays. It is creamy, savory, and topped with those irresistible crunchy onions. But if you are ready to change up the usual side dish routine, this green pea casserole is a delicious option.
Instead of green beans, this recipe uses sweet green peas. The peas pair beautifully with the creamy mushroom sauce, melted cheddar cheese, and golden onion topping. The result is familiar, nostalgic, and slightly different in the best possible way.
The homemade cream sauce is easy to prepare and gives the casserole a rich, smooth texture without much extra work. It is a great alternative to creamed peas and a simple way to turn frozen peas into a warm, satisfying side dish.
Serve this cheesy pea casserole with meatloaf, roasted chicken, pork chops, turkey, ham, or any main dish that needs a creamy vegetable side. It is also a strong choice for potlucks and holiday tables because it is easy to assemble, easy to bake, and comforting enough for guests of all ages.
See the recipe card for complete ingredient amounts and detailed instructions.
Ingredient Notes
- Green peas – Frozen peas work very well because they hold their shape and have a naturally sweet flavor. Canned peas can also be used, but they should be drained and rinsed well. Keep in mind that canned peas may become softer after baking.
- Half & Half – This helps create a creamy sauce for the casserole. Milk can be used if needed, while heavy cream will make the sauce richer. Chicken stock or vegetable broth can be used for a lighter version.
- Cheese – Mild or medium cheddar cheese gives the casserole a classic flavor. You can use another favorite melting cheese if preferred.
- Mushrooms – Canned sliced mushrooms make prep quick and easy. If using fresh mushrooms, cook them with the onion and garlic before adding the flour.
- French fried onions – These add the crunchy topping that makes this casserole so good. Corn flakes, cracker crumbs, or panko can be used instead. A little Parmesan cheese can also be sprinkled over the top for extra flavor.
How To Make Green Pea Casserole
- Preheat the oven to 350F and thaw the peas. Melt the butter in a large skillet over medium heat. Add the onion and garlic, then cook for 1 to 2 minutes, until softened and fragrant.
- Sprinkle in the flour and whisk until combined. Cook for 1 to 2 minutes to remove the raw flour taste. Slowly whisk in the half & half and continue cooking until the sauce thickens enough to coat the back of a spoon. Remove from the heat.
- Coat a 9×13 baking dish with nonstick cooking spray. In a large bowl, combine the peas, mushrooms, shredded cheese, and cream sauce. Stir until everything is evenly mixed, then spread the mixture in the prepared baking dish.
- Bake uncovered at 350F for 20 minutes. Remove the dish from the oven, sprinkle the French fried onions evenly over the top, and bake for 5 more minutes. Serve warm.
For exact measurements and step-by-step details, use the recipe card below.
Storage
Store leftover green pea casserole in an airtight container in the refrigerator for up to 4 days. Reheat individual portions in the microwave, or warm larger portions in a skillet or oven until heated through.
Prep Ahead
You can prepare the casserole filling about 1 day in advance. Mix the peas, mushrooms, cheese, and cream sauce, then cover the dish tightly or store the filling in an airtight container in the refrigerator. Do not add the fried onion topping until baking time, or it may become soft.
Before baking, remove the casserole from the refrigerator and let it sit at room temperature for about 15 minutes. Bake as directed, adding the fried onions after the first 20 minutes.
This casserole can also be frozen for up to 3 months in an airtight container. For the best texture, freeze it without the onion topping and add the topping just before the final bake. Thaw overnight in the refrigerator before reheating.
Variations
This green pea casserole recipe is delicious as written, but it is also easy to adjust based on what you have on hand.
- Use condensed cream soup instead of making the roux if you need a shortcut.
- Replace the fried onions with crushed crackers, corn flakes, or panko bread crumbs.
- Leave out the mushrooms if you do not enjoy them.
- Add pearl onions for a sweeter onion flavor.
- Stir in cooked, chopped bacon for a smoky addition.
- Add pimentos for a little color and mild flavor.
Making A Cream Sauce
- Start with medium heat: Melt the butter gently, then cook the onion and garlic until they soften. Avoid high heat so the garlic does not burn.
- Cook the flour: Sprinkle the flour over the vegetables and whisk until coated. Let it cook for 1 to 2 minutes so the finished sauce does not taste floury.
- Add liquid slowly: Pour in the half & half gradually while whisking. This helps prevent lumps and creates a smoother sauce.
- Watch the texture: The sauce is ready when it thickens and coats the back of a spoon. It should bubble gently, but it does not need to boil hard.
- Use a shortcut if needed: If you do not want to make a roux, condensed cream soup can be used as an easy alternative.
Recipe Tips & Tricks
- Thicken a thin sauce – If the sauce is too loose, whisk in a small amount of flour or cornstarch and cook until thickened.
- Change the soup flavor – If using condensed soup as a shortcut, cream of mushroom is classic, but cheddar cheese soup also works well.
- Use leftovers creatively – Leftover casserole can be stirred into pasta, added to pot pie filling, mixed into hash, or used as a filling for stuffed mushrooms.
- Serve warm – This casserole tastes best when the sauce is hot and creamy and the onion topping is crisp.
This easy green pea casserole is creamy, cheesy, and perfect for busy weeknights, holidays, and family dinners.
Green Pea Casserole Recipe
Ingredients
- ¼ cup butter
- ½ cup onion finely chopped
- 1 clove garlic minced
- 2 tablespoons all-purpose flour
- ½ teaspoon salt
- ½ teaspoon black pepper
- 1 ½ cups half & half
- 1 ½ cups cheddar cheese shredded
- 32 ounces frozen peas thawed
- 4 ounces canned mushrooms drained and rinsed
- 6 ounces French fried onions
Instructions
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Preheat the oven to 350F. Remove the peas from the freezer and let them thaw.
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Melt the butter in a medium skillet over medium heat.
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Add the onion and garlic. Cook for 1 to 2 minutes, until the onion softens and the garlic is fragrant.
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Add the flour and whisk to combine. Cook for 1 to 2 minutes.
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Slowly whisk in the half & half. Continue whisking until the sauce thickens and coats the back of a spoon.
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Remove the sauce from the heat.
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Coat a 9×13 baking dish with nonstick cooking spray.
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In a large bowl, combine the thawed peas, drained mushrooms, shredded cheese, and thickened onion-garlic sauce.
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Stir until evenly combined.
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Pour the mixture into the prepared baking dish and spread it evenly.
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Bake at 350F for 20 minutes.
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Remove the casserole from the oven and spread the fried onions evenly over the top.
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Bake for 5 additional minutes.
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Remove from the oven and serve warm.
Notes
- Fix thin sauce – If the sauce is too thin, whisk in a small amount of flour or cornstarch and cook until thickened.
- Soup swap – Condensed cream soup can be used instead of the homemade sauce for a quicker version.
- Repurpose leftovers – Add leftovers to pot pie filling, stuffed mushrooms, hash, or pasta.
- Best texture – Add the fried onions near the end of baking so they stay crisp.
Nutrition
