The EASIEST Green Bean Casserole (with frozen green beans!)

This easy green bean casserole starts with a bag of frozen green beans and only six simple ingredients, and it comes out rich, creamy, and topped with melty cheddar and crispy fried onions. It's the no-fuss version of the classic, perfect for Thanksgiving or any weeknight!

This post brought to you by Campbell’s Soup Company. The content and opinions expressed below are mine.

Did you know that you can add a tremendous amount of flavor to a vegetable side dish by cooking the vegetables in chicken broth? Yep, it's such an easy trick that can bring more flavor to so many veggie side dishes. It's a simple idea really, but the amount of flavor you get by simply switching out water for broth is out of this world.

I used Swanson® Broth to create this Green Bean Casserole that is a family favorite. It's usually reserved for Thanksgiving, but sometimes I'll pull out this old classic just for a fun weeknight dinner. And I've made things even easier by using two other simple items: cream of mushroom soup and frozen green beans. Yes, frozen! It only needs six ingredients and it's ready in under an hour, and most of that time is just the baking time.

Why Frozen Green Beans Work So Well

Frozen green beans are picked and blanched at their peak, so they're already tender, bright green, and trimmed for you. There's no snapping off ends and no waiting for a pot of water to boil, and a bag keeps in the freezer for months, which means you can make this casserole on short notice any time of year. Cut green beans are the classic choice, but French-style (thin sliced) frozen beans work too and give you that old-fashioned holiday texture.

Do You Need to Thaw Frozen Green Beans for Green Bean Casserole?

No! In this recipe, the green beans go straight from the freezer into a pot of simmering broth. Four or five minutes in the broth thaws them, seasons them, and cooks them just to crisp-tender, so they finish perfectly in the oven. The one step you shouldn't skip is draining them well afterward, since extra liquid will thin out the creamy sauce. If you'd rather skip the stovetop entirely, you can thaw the beans overnight in the fridge, pat them very dry, and stir them straight into the sauce; the casserole will just need a few extra minutes in the oven.

How Long to Bake Green Bean Casserole with Frozen Green Beans

Bake it at 350°F for 30 minutes, until the sauce is bubbling around the edges. Then add the rest of the cheese and fried onions and bake 5 to 7 minutes more, just until the cheese melts and the onions turn golden. That's about 35 to 37 minutes in the oven total. If you use thawed beans that haven't been simmered first, plan on 35 to 40 minutes before adding the topping.

Key Ingredients & Substitutions

• Frozen green beans. A 16-ounce bag of cut green beans is all you need. French-cut beans work too. If you have fresh green beans, trim and cut them into 1 ½-inch pieces and simmer them in the broth for 6 to 8 minutes instead.
• Chicken broth. This is the secret to flavorful beans. I love Swanson Unsalted Chicken Broth since it lets you control the salt. Use vegetable broth to keep the casserole vegetarian.
• Cream of mushroom soup. One 10.5-ounce can of Campbell's condensed cream of mushroom soup makes the creamy base. Cream of chicken or cream of celery soup are easy swaps.
• Milk. Loosens the condensed soup into a silky sauce. Any milk works; half-and-half makes it richer.
• Cheddar cheese. Half goes into the casserole and half on top. Shred your own from a block for the smoothest melt. Colby jack, Gruyere, or Swiss are all delicious alternatives.
• French fried onions. The crunchy topping everyone fights over. French's Crispy Fried Onions are the classic choice; crushed buttery crackers or panko toasted in butter work in a pinch.

Helpful Tips

Don't overcook the beans on the stove. Pull the frozen green beans off the heat as soon as they're bright green and just tender, about 4 to 5 minutes. They keep cooking in the oven, and beans that start out soft will turn mushy by the time the casserole is done.

Drain them really well. Frozen vegetables hold onto water. Let the beans sit in a colander for a minute or two after draining, and give them a shake, so the sauce stays thick and creamy instead of watery.

Save some broth. Scoop out a few tablespoons of the cooking broth before you drain. If the sauce looks too thick once everything is mixed, a splash of broth thins it out and adds even more flavor.

Add the topping in two stages. Mixing half the fried onions into the casserole gives you flavor in every bite, while adding the rest at the end keeps the top crunchy. If the onions brown too quickly, lay a piece of foil loosely over the dish.

Double it for a crowd. The recipe doubles easily. Use two bags of frozen green beans and bake it in a 9x13-inch dish, adding 5 to 10 minutes to the first bake.

Variations

• From scratch (no canned soup). Melt 3 tablespoons of butter in a skillet, cook 8 ounces of sliced mushrooms and a minced garlic clove until browned, then stir in 3 tablespoons of flour. Slowly whisk in 1 cup of broth and 1 cup of milk and simmer until thick. Season with salt and pepper and use it in place of the soup and milk.
• Bacon green bean casserole. Cook 4 to 6 slices of bacon until crisp, crumble, and stir half into the casserole and sprinkle the rest over the top with the onions.
• Extra cheesy. Stir 2 ounces of softened cream cheese into the soup mixture and use a mix of cheddar and Parmesan on top.
• Mushroom lover's. Saute a cup of sliced fresh mushrooms in butter and fold them in with the beans for a more classic mushroom flavor.
• A little heat. Use pepper jack instead of cheddar and add a pinch of cayenne or a few dashes of hot sauce to the sauce.

Serving Ideas

This casserole is a must on the holiday table next to roast turkey (need ideas? try one of these creative turkey recipes for Thanksgiving), easy garlic mashed potatoes, and cranberry pecan stuffing.

It's just as good with Christmas or Easter dinner alongside an easy 3-ingredient glazed ham, or on a regular weeknight with roast chicken or pork chops. Want another freezer-friendly side? Pair it with this 15-minute creamed corn made from frozen corn.

Make-Ahead

This is a great make-ahead holiday side. Cook and drain the frozen green beans, mix them with the soup, milk, and half the cheese, and spread everything in the baking dish. Cover tightly and refrigerate for up to 2 days. Keep the fried onions and remaining cheese separate so they stay crisp.

When you're ready to bake, let the dish sit on the counter for about 20 minutes while the oven heats. Stir in half the fried onions, then bake at 350°F for 35 to 40 minutes, until bubbly. Add the remaining cheese and onions and bake 5 to 7 minutes more.

Storing & Reheating

Let leftovers cool, then cover the dish or move them to an airtight container and refrigerate for up to 4 days. Reheat individual portions in the microwave, or cover the dish with foil and warm it in a 350°F oven for 15 to 20 minutes. Uncover for the last few minutes (and add a handful of fresh fried onions if you have them) to bring back the crunch.

You can freeze the casserole before adding the topping. Assemble it in a freezer-safe dish, wrap it tightly, and freeze for up to 3 months. Thaw it overnight in the refrigerator, then bake as directed in the make-ahead section. Freezing a fully baked casserole isn't ideal, since the onions go soft and the sauce can separate a little, but it's still tasty reheated.

More Holiday Side Dishes

If you love this easy green bean casserole, be sure to check out these other delicious recipes:

• Green Beans with Caramelized Onions
• Parmesan Green Beans
• Apple Butternut Squash Casserole with Bacon Pecan Topping
• Cheesy Baked Pierogy Casserole

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