Green Bean Casserole From Scratch
This homemade green bean casserole uses fresh green beans, a creamy mushroom sauce made without canned soup, and crispy fried onions for a classic holiday side dish with fresh flavor and a rich, comforting texture.
Prep
25 min
Cook
35 min
Total
1 hr
Servings
8 servings (about 8 cups)
Ingredients
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Instructions
- 1
Preheat the oven to 375°F. Bring a large pot of salted water to a boil, add the fresh green beans, and blanch for 4–5 minutes until bright green and crisp-tender. Drain and rinse under cold water to stop the cooking, then set aside. It's ready when the beans are bright green and a fork can pierce them with slight resistance.
- 2
Melt 2 tablespoons of butter in a large skillet over medium heat. Add the diced onion and sliced mushrooms and cook for 7–8 minutes, stirring occasionally, until the mushrooms release their moisture and begin to brown. Stir in the minced garlic and cook for 30 seconds. It's ready when the mushrooms have softened, most of their liquid has evaporated, and the garlic smells fragrant.
- 3
Add the remaining 2 tablespoons of butter to the skillet. Once melted, sprinkle in the flour and whisk continuously over medium heat for 1–2 minutes to form a smooth roux. It's ready when the flour is lightly golden and no dry patches remain.
- 4
Gradually whisk in the vegetable broth, followed by the milk and heavy cream. Add the soy sauce, salt, black pepper, and optional thyme. Simmer over medium-low heat for 4–6 minutes, whisking frequently, until the sauce thickens. It's ready when the sauce is smooth, creamy, and thick enough to coat the back of a spoon.
- 5
Add the drained green beans to the skillet and stir gently until they are evenly coated in the mushroom sauce. Remove from the heat and fold in 1/2 cup of the crispy fried onions (about 2 minutes). It's ready when every green bean is coated with sauce and the onions are evenly distributed.
- 6
Transfer the green bean mixture to a 9×13-inch baking dish and spread it into an even layer. Sprinkle the remaining 1 cup of crispy fried onions over the top (about 2 minutes).
- 7
Bake uncovered at 375°F for 15–18 minutes, until the casserole is bubbling around the edges and the onion topping is golden brown. Let rest for 5 minutes before serving. It's ready when the sauce bubbles around the edges and the crispy onion topping is golden and crunchy.
Used in this recipe: 9×13 Baking Dish Stainless Steel Whisk (Amazon, affiliate links)
Notes
Tips for Success
- Blanching fresh green beans before baking is essential for achieving a tender texture without overcooking the creamy sauce. Cooking the mushrooms until their moisture evaporates also concentrates their flavor and prevents a watery casserole.
- Drain the blanched green beans thoroughly and pat them dry if needed. Cook the mushrooms until their released liquid has evaporated before adding the flour. Whisk the sauce until it thickens before combining it with the beans. If the casserole is already watery, bake it uncovered for a few additional minutes to allow excess moisture to evaporate.
Common Mistakes to Avoid
- The casserole can become watery if the fresh green beans retain too much moisture or the mushrooms are added before their liquid has evaporated. The sauce may also become too thin if the roux is not cooked properly.
Nutrition (per serving)
240 kcal
Calories
6g
Protein
22g
Carbs
16g
Fat
4g
Fiber
510mg
Sodium
This green bean casserole is made from scratch with fresh green beans, a creamy mushroom sauce, and crispy fried onions—without canned condensed soup. Blanching the beans before baking keeps them tender, while browning the mushrooms concentrates their savory flavor.
Ingredients
- Fresh green beans: Choose firm beans for the best texture. Blanching them before baking helps them stay tender without becoming mushy.
- Unsalted butter: Builds flavor and helps form the roux that thickens the mushroom sauce.
- Yellow onion and garlic: Add a savory base to the sauce.
- Cremini mushrooms: Bring an earthy flavor to the homemade sauce.
- All-purpose flour: Thickens the sauce so it clings to the green beans instead of pooling at the bottom.
- Vegetable broth: Adds savory depth without relying on canned soup.
- Whole milk and heavy cream: Create a smooth, creamy sauce.
- Soy sauce: Adds savory richness and rounds out the mushroom flavor.
- Salt and freshly ground black pepper: Season the sauce.
- Crispy fried onions: Add crunch and the familiar flavor of classic green bean casserole.
- Fresh thyme (optional): Adds an earthy herbal note.
How To Make It
The key to homemade green bean casserole is controlling moisture at each stage. Drain the beans well, cook the mushrooms until their liquid evaporates, and thicken the sauce before combining everything.
1. Blanch the fresh green beans
Cook the green beans in boiling salted water until they turn bright green and are crisp-tender. A fork should pierce a bean with slight resistance. Drain them in a colander, rinse under cold water to stop the cooking, and let the excess water drain away.
2. Cook the mushrooms and onion
Melt some of the butter in a large skillet over medium heat. Add the diced onion and sliced mushrooms, stirring occasionally as they soften and release their moisture. Let the liquid evaporate before adding the garlic. The mushrooms should begin to brown, and the garlic should smell fragrant after cooking.
3. Make the roux
Add the remaining butter to the skillet. Once melted, sprinkle in the flour and whisk continuously over medium heat. The mixture should become smooth and lightly golden, with no dry patches of flour. Cooking the flour this way helps thicken the sauce without leaving a raw flour taste.
4. Build the creamy mushroom sauce
Gradually whisk in the vegetable broth, followed by the milk and heavy cream. Stir in the soy sauce, salt, black pepper, and optional thyme. Simmer over medium-low heat, whisking frequently. The sauce is ready when it looks smooth and creamy and coats the back of a spoon. It should be thick enough to cling to the beans rather than run off them.
5. Combine the beans and sauce
Add the drained green beans to the skillet and stir gently until each piece is coated. Remove the skillet from the heat and fold in some of the crispy fried onions. The onions mixed into the casserole add flavor throughout, while the remaining onions provide the crunchy topping.
6. Assemble and bake
Transfer the mixture to a baking dish and spread it into an even layer. Sprinkle the remaining crispy fried onions over the top. Bake uncovered until the sauce bubbles around the edges and the topping turns golden brown and crunchy. Let the casserole rest briefly before serving so the sauce can settle.
Why Blanching the Green Beans Matters
Fresh green beans need a head start before they go into the oven. Blanching softens them while preserving enough firmness to withstand baking in the creamy sauce. Skipping this step can leave the beans too firm by the time the casserole is heated through. Cooking them too long in the boiling water can have the opposite effect, leaving them overly soft after baking. The mushrooms matter just as much. They release liquid as they cook, and that moisture needs to evaporate before the flour and liquids are added. Browning them first concentrates their savory flavor and helps the finished sauce stay creamy instead of watery.
How to Keep Green Bean Casserole From Being Watery
A watery casserole usually comes down to excess moisture in the vegetables or a sauce that has not thickened enough.
- Drain the beans thoroughly. Water clinging to the blanched beans can thin the sauce. Pat them dry if needed.
- Let the mushrooms brown. Wait until most of their released liquid has evaporated before adding the flour.
- Cook the roux properly. Whisk the flour and butter until the mixture is smooth and lightly golden, with no dry flour remaining.
- Thicken the sauce before combining. It should coat the back of a spoon before the beans are added. If the casserole is already watery, return it to the oven uncovered for a few additional minutes to let excess moisture evaporate. Keep an eye on the onion topping so it does not become too dark.
Substitutions
These are untested alternatives, so expect some differences in flavor or texture.
- Cremini mushrooms: White button mushrooms are a possible substitute. They have a milder mushroom flavor but a similar texture.
- Whole milk: Half-and-half can be used instead. The sauce will be richer and creamier.
- Vegetable broth: Chicken broth is an option if the dish does not need to be vegetarian. It will give the sauce a deeper savory flavor.
- Crispy fried onions: Panko breadcrumbs are another possible topping. Toss them with a little melted butter before adding them. The result will be lighter and crunchier, with less onion flavor.
Make-Ahead Instructions
Blanch the green beans and prepare the mushroom sauce up to 2 days ahead. Refrigerate promptly in separate airtight containers; storage time begins when each component is cooked. Combine the cold beans and sauce in the baking dish without the onion topping. Bake at 375°F for about 20–25 minutes, or longer as needed to reach 165°F throughout. Add the crispy fried onions during the final 10–15 minutes of baking.
Storage and Reheating
Refrigerate leftover green bean casserole in an airtight container within 2 hours of cooking. It keeps for up to 3–4 days in the refrigerator. To reheat, warm individual portions in the microwave or heat the casserole in a 350°F oven until it reaches 165°F throughout. The onion topping will soften during storage, so it may not be as crunchy as when freshly baked. For more guidance on storing and reheating leftovers safely, see the USDA’s Leftovers and Food Safety recommendations. Freezing is also possible for up to 2 months. The creamy sauce may separate slightly after thawing, and the green beans may become softer.
What to Serve With Green Bean Casserole
The creamy mushroom sauce and crispy onion topping pair well with classic comfort-food sides and a holiday main dish.
- Roasted turkey: A traditional pairing for a holiday meal.
- Garlic mashed potatoes: Their smooth texture complements the green beans and creamy sauce.
- Honey-glazed carrots: Add a touch of sweetness alongside the savory mushrooms.
- Homemade dinner rolls: Use them to scoop up any extra sauce on the plate. For a fresh side to balance the creamy casserole, try this easy goat cheese beet salad with fresh greens.
FAQ
How do you make green bean casserole from scratch?
Blanch fresh green beans, cook mushrooms and onion until their moisture evaporates, then prepare a roux-based sauce with broth, milk, and cream. Combine the beans and sauce, add crispy fried onions, and bake until bubbling with a golden topping.
Can you use fresh green beans in green bean casserole?
Yes. Fresh green beans are a good choice for a homemade casserole. Blanching them before baking helps them become tender while keeping their texture intact.
Can green bean casserole be made ahead of time?
Yes. Prepare the blanched green beans and mushroom sauce up to 2 days ahead and refrigerate them separately. Assemble the casserole when ready to bake, adding the crispy onion topping toward the end if starting with cold ingredients.
How do you keep green bean casserole from being watery?
Drain the green beans thoroughly, cook the mushrooms until most of their liquid evaporates, and let the sauce thicken before combining everything. If the casserole is already watery, bake it uncovered for a few additional minutes to help excess moisture evaporate.
