Description
This homemade Green Bean Casserole recipe from scratch features crispy fried onions, tender green beans, and a rich creamy mushroom sauce made with fresh ingredients. Perfect as a comforting side dish for holiday dinners or family meals, it offers a delicious upgrade to the classic casserole using homemade fried onions and scratch-made cream of mushroom sauce.
Ingredients
Scale
Fried Onions
- 1 yellow onion thinly sliced
- 1 red onion thinly sliced
- 2 1/2 cups buttermilk (see DIY below)
- 1 1/2 cups all-purpose flour
- 1 cup panko breadcrumbs
- 1/2 tsp salt
- 1/2 tsp pepper
- vegetable or canola oil for frying
Green Beans
- 1 3/4 pounds (28 oz) green beans trimmed and cut in half
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 12 oz. cremini mushrooms sliced ¼” thick
- 4 garlic cloves minced
- 1 teaspoon salt
- 1/3 cup all-purpose flour
- 3 cups low sodium chicken broth
- 1/2 cup heavy cream
- 1 1/2 teaspoons Dijon mustard
- 1 1/2 teaspoons Worcestershire sauce
- 1 tsp dried thyme
- 1 tsp dried parsley
- 1/2 teaspoon pepper
- 1/4 tsp dried oregano
- 1/4 tsp nutmeg
- 1/2 cup freshly grated cheddar cheese
- 1/4 cup freshly grated Parmesan cheese
- 1/2 cup sour cream
Instructions
- Soak Onions: Add thinly sliced yellow and red onions to a shallow baking dish and pour buttermilk over them. Press the onions down to submerge as much as possible. Let soak at room temperature for 1 hour, stirring occasionally. Cover and refrigerate if soaking longer.
- Prepare Frying Oil and Coating: Heat vegetable or canola oil in a Dutch oven or heavy pot to 375 degrees F with about 2 inches of oil. Meanwhile, combine flour, panko breadcrumbs, salt, and pepper in a large bowl. Line a baking sheet with paper towels for draining.
- Fry Onions: Test oil temperature by dropping a pinch of panko; if it bubbles, oil is ready. Use tongs to transfer a handful of soaked onions to the flour mixture, toss to coat, shake off excess, then carefully add to hot oil. Fry for 1-2 minutes until lightly golden. Remove with slotted spoon and drain on paper towels. Repeat with remaining onions.
- Blanch Green Beans: Bring large pot of water to boil with 2 tablespoons salt. Add green beans and blanch for 5 minutes. Immediately transfer beans to ice water to stop cooking. Drain and pat dry.
- Cook Mushrooms and Garlic: Melt butter with olive oil over medium heat in a large pot or Dutch oven. Add mushrooms and cook 3-5 minutes until browned and softened. Season with salt and add garlic; sauté 30 seconds.
- Make Sauce: Whisk in flour and cook for 1 minute. Turn heat to low and gradually whisk in chicken broth and heavy cream. Add Dijon mustard, Worcestershire sauce, dried thyme, parsley, pepper, oregano, and nutmeg. Bring to boil while whisking constantly, then reduce heat and simmer, whisking often, until thickened about 5 minutes.
- Add Cheeses and Sour Cream: Remove from heat and whisk in cheddar cheese, then Parmesan cheese until melted. Whisk in sour cream until smooth.
- Combine Green Beans and Sauce: Stir dried green beans and 1 ½ cups of fried onions into the sauce. Add extra broth if needed to thin sauce to desired consistency.
- Assemble and Bake: Transfer mixture to a lightly greased 9×13 inch baking dish. Top with remaining fried onions. Bake at 350 degrees F for 15-20 minutes until hot and bubbly.
Notes
- DIY Buttermilk: Combine 2 ½ tablespoons lemon juice or white vinegar with enough milk to equal 2 ½ cups; stir and let sit 10-15 minutes before using. Add a splash of heavy cream if using low-fat milk.
- Use pre-cut green beans to save prep time but still trim and cut in half for best texture.
- Pat green beans very dry before adding to sauce to avoid excess moisture.
- Brown mushrooms fully to enhance flavor; delay adding salt until after mushrooms brown.
- Cook flour for at least 1-2 minutes to remove raw taste and develop nutty flavor.
- Simmer sauce on low to prevent lumps and allow proper thickening without becoming too thick as cheese and sour cream are added later.
- If sauce becomes too thick, thin with additional chicken broth as needed.
- Sliced onions can be prepared a day ahead and stored refrigerated.
- Maintain oil temperature around 375°F for optimal frying; test with panko breadcrumbs before frying onions.
- Fry onions only until lightly golden since they will continue cooking in the oven; over-frying can make them too dark.
- For make-ahead meals, fry onions and store at room temperature up to 3 days; prepare green beans and sauce separately and refrigerate up to 48 hours before combining and baking.
- Store leftover casserole in an airtight container in the refrigerator for up to 5 days; onions may lose crispness upon reheating.
Nutrition
- Serving Size: 1 cup
- Calories: 280 kcal
- Sugar: 3 g
- Sodium: 450 mg
- Fat: 18 g
- Saturated Fat: 7 g
- Unsaturated Fat: 9 g
- Trans Fat: 0 g
- Carbohydrates: 20 g
- Fiber: 4 g
- Protein: 7 g
- Cholesterol: 40 mg
