# What You Need:
→ Vegetables
01 - 1 lb fresh green beans, trimmed and cut into 2-inch pieces (or 1 lb frozen, thawed)
02 - 1 small yellow onion, finely chopped
03 - 2 cloves garlic, minced
04 - 8 oz cremini or button mushrooms, sliced
→ Sauce
05 - 2 tablespoons unsalted butter
06 - 2 tablespoons all-purpose flour
07 - 1 cup whole milk
08 - 1/2 cup low-sodium vegetable broth
09 - 1/2 cup sour cream
10 - 1/2 teaspoon salt
11 - 1/4 teaspoon black pepper
12 - 1/4 teaspoon ground nutmeg
→ Topping
13 - 1 1/2 cups crispy fried onions (store-bought or homemade)
# Directions:
01 - Preheat oven to 350°F.
02 - Bring a large pot of salted water to a boil, add green beans, and cook for 4–5 minutes until bright green and just tender. Drain and transfer immediately to ice water to halt cooking. Drain again and set aside.
03 - In a large skillet over medium heat, melt butter. Add chopped onion and cook for 2–3 minutes until softened. Add garlic and mushrooms; cook for 5 minutes until mushrooms are tender and liquid evaporates.
04 - Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk and vegetable broth and cook, stirring, until sauce thickens, about 3–4 minutes.
05 - Remove skillet from heat. Stir in sour cream, salt, pepper, and ground nutmeg until smooth.
06 - Add drained green beans to sauce and mix until evenly coated.
07 - Transfer mixture to a greased 2-quart baking dish. Sprinkle 1 cup of crispy fried onions evenly on top.
08 - Bake for 25 minutes until bubbling.
09 - Remove from oven, top with remaining crispy fried onions, and bake an additional 5 minutes until golden brown.
10 - Let rest for 5 minutes prior to serving.