Classic Vegetarian Green Bean Casserole is a homemade version of the traditional holiday side dish, made with tender green beans, sautéed mushrooms, and a creamy sauce. Vegetable broth and everyday pantry ingredients create a rich base without using condensed cream of mushroom soup.
The green beans stay tender beneath the savory mushroom sauce, while crispy fried onions add a crunchy contrast. This baked casserole fits naturally into Thanksgiving menus, holiday dinners, and Sunday meals when you want a vegetable side that can be prepared ahead.
Why This Green Bean Casserole Works So Well
- Homemade Cream Sauce: Flour, milk, and vegetable broth create a creamy base without relying on canned soup.
- Simple Preparation: The sauce comes together in a skillet before the ingredients move to the oven.
- Vegetarian-Friendly: Vegetable broth keeps the recipe suitable for vegetarian menus when the other packaged ingredients are also vegetarian.
- Convenient for Holidays: Several components can be prepared ahead to reduce kitchen work on the day of your gathering.
- Easy to Portion: A 2-quart casserole dish makes it convenient to serve alongside other holiday dishes.
Ingredient Notes and Easy Substitutions
- Fresh Green Beans: Choose firm, bright green beans without brown spots. Trim the ends and cut them into evenly sized pieces for consistent cooking. Frozen green beans are another option when thawed and drained thoroughly.
- Cremini or Button Mushrooms: Both varieties work well in the sauce. Cremini mushrooms have a slightly deeper, earthier taste, while button mushrooms offer a milder option.
- Unsalted Butter: Butter helps cook the mushrooms and provides a rich base for the sauce. Unsalted butter also makes it easier to control the final salt level.
- All-Purpose Flour: Flour thickens the broth and milk into a sauce that clings to the green beans. Cook it with the mushrooms briefly before adding the liquids.
- Vegetable Broth and Whole Milk: Vegetable broth supplies savory depth, while whole milk adds creaminess. Use a low-sodium broth if you want more control over the seasoning.
Chef’s Tip: Add the vegetable broth gradually while whisking, then pour in the milk. This helps the flour incorporate evenly and reduces the chance of lumps forming in the sauce.
Classic Vegetarian Green Bean Casserole
Classic Vegetarian Green Bean Casserole features tender green beans baked in a creamy mushroom sauce and topped with crispy fried onions. The combination of savory mushrooms, garlic, and a smooth, seasoned sauce makes this traditional side dish a comforting addition to any meal.Made with fresh green beans, vegetable broth, and simple pantry ingredients, this homemade green bean casserole delivers classic flavor without relying on condensed soup. It is an excellent choice for Thanksgiving dinner, holiday gatherings, or Sunday meals when a warm vegetable side belongs on the table.
Equipment
- Large pot
- Colander
- Large skillet
- Whisk or wooden spoon
- 2-quart casserole dish
- Measuring cups and spoons
- Cutting board and knife
Ingredients
- 1 1/2 pounds fresh green beans trimmed and cut into 2-inch pieces
- 3 tablespoons unsalted butter
- 10 ounces cremini or button mushrooms sliced
- 2 garlic cloves minced
- 3 tablespoons all-purpose flour
- 1 1/2 cups low-sodium vegetable broth
- 1 cup whole milk
- 1 teaspoon soy sauce
- 1/2 teaspoon salt or to taste
- 1/4 teaspoon freshly ground black pepper
- 1/4 teaspoon ground nutmeg
- 1 1/2 cups crispy fried onions divided
Instructions
- Prepare the oven and green beans. Preheat the oven to 375°F (190°C). Bring a large pot of salted water to a boil. Add the green beans and cook for 4 to 5 minutes, until bright green and just tender. Drain well and set aside.
- Cook the mushrooms. Melt the butter in a large skillet over medium heat. Add the sliced mushrooms and cook for 6 to 8 minutes, stirring occasionally, until they release their moisture and begin to turn golden brown. Add the minced garlic and cook for another 30 seconds, until fragrant.
- Make the creamy sauce. Sprinkle the flour over the mushrooms and stir until evenly coated. Cook for 1 to 2 minutes to remove the raw flour taste. Gradually whisk in the vegetable broth, followed by the milk, until the mixture is smooth. Add the soy sauce, salt, black pepper, and nutmeg.
- Simmer until thickened. Cook the sauce over medium-low heat for 3 to 5 minutes, stirring frequently, until it thickens enough to coat the back of a spoon. Taste and adjust the seasoning as needed.
- Combine the casserole. Add the drained green beans and 1 cup of the crispy fried onions to the skillet. Stir gently until the beans are evenly coated in the mushroom sauce. Transfer the mixture to a 2-quart casserole dish and spread it into an even layer.
- Bake until bubbly. Place the casserole in the preheated oven and bake for 15 minutes, until the sauce is bubbling around the edges and the beans are heated through.
- Add the crispy topping. Sprinkle the remaining 1/2 cup of fried onions evenly over the casserole. Return it to the oven for another 5 to 8 minutes, until the topping is golden and crisp.
- Rest and serve. Let the casserole rest for about 5 minutes before serving. This allows the sauce to settle slightly while keeping the onion topping crisp.
Notes
- Fresh or frozen green beans: Fresh green beans provide a slightly firmer texture. Frozen green beans can also be used; thaw and drain them thoroughly before adding them to the sauce.
- Keep it vegetarian: Choose vegetable broth and check the ingredients on packaged fried onions to ensure they are suitable for a vegetarian diet.
- Avoid a watery casserole: Drain the green beans well and allow the mushroom sauce to thicken before combining everything.
- Make-ahead option: Prepare the green beans and mushroom sauce, combine them in the casserole dish, cover, and refrigerate for up to 24 hours. Add the crispy onion topping near the end of baking.
- Storage: Refrigerate leftovers in an airtight container for up to 4 days. Reheat in a 350°F (175°C) oven until warmed through.
- Crispy topping: Add the fried onions during the final minutes of baking rather than at the beginning to prevent them from becoming soggy.
- Nutrition estimate: Values are approximate and depend on the brands of vegetable broth, milk, and crispy fried onions used.
Nutrition Information
| Nutrient | Amount |
|---|---|
| Calories | 240 kcal |
| Carbohydrates | 22 g |
| Protein | 7 g |
| Fat | 15 g |
| Fiber | 5 g |
| Sugar | 7 g |
| Sodium | 470 mg |
Delicious Variations to Try
- Cheesy Green Bean Casserole: Stir shredded sharp cheddar into the sauce before combining it with the green beans.
- Herb-Seasoned Casserole: Mix in a little fresh thyme or chopped parsley for an herbal note.
- Gluten-Free Casserole: Use a suitable gluten-free flour blend and verify that the fried onion topping and other packaged ingredients are gluten-free.
- Lighter Sauce: Substitute reduced-fat milk for whole milk, keeping in mind that the sauce may be less rich.
- Spicy Mushroom Casserole: Add a small pinch of crushed red pepper flakes to the sauce for gentle heat.
More Vegetable Side Dish Recipes to Try
- One Pan Coconut Curry Shrimp Recipe
- Keto Thai Curry Chicken Soup Recipe
- Shrimp And Crab Dip Recipe
- Crockpot Ham Recipe
- Sausage Stuffed Mushroom Recipe
Frequently Asked Questions
- Can I use canned green beans for this casserole?
Yes. Drain them thoroughly before mixing them into the sauce. Since canned green beans are already cooked, handle them gently to avoid breaking them apart. - How do I know when the mushroom sauce is thick enough?
Dip a spoon into the sauce and check whether it coats the back rather than running off immediately. - Can I make this casserole without mushrooms?
Yes, although the sauce will have a different flavor. You can leave them out, but you may need to adjust the seasoning to maintain the savory depth. - Why does the recipe use nutmeg?
A small amount of nutmeg adds warmth and complements the creamy milk-based sauce. It should remain subtle rather than taste strongly of spice. - Can I use a different plant-based milk?
Unsweetened, unflavored plant milk can work, particularly oat or soy milk. Choose one without added sweetness, and expect some differences in the sauce’s richness and thickness. - How can I tell when the casserole is fully baked?
Look for bubbling sauce around the edges, heated-through green beans, and a golden, crisp onion topping. - Is soy sauce necessary in green bean casserole?
Soy sauce adds a savory note, but the recipe can be made without it. If omitted, taste the sauce and adjust the salt and pepper as needed. - Can I double this recipe for a large gathering?
Yes. Double the ingredients and divide the mixture between two casserole dishes rather than overcrowding one dish.
