# What You'll Need:
→ Vegetables
01 - 2 lb fresh green beans, trimmed and cut into 2-inch pieces (or 2 lb frozen cut green beans, thawed and drained)
→ Sauce Base
02 - 2 tbsp unsalted butter
03 - 9 oz cremini or button mushrooms, sliced
04 - 1 small yellow onion, finely chopped
05 - 2 garlic cloves, minced
06 - 2 tbsp all-purpose flour
07 - 1 cup whole milk
08 - ½ cup heavy cream
09 - ½ cup low-sodium vegetable broth
10 - 1 tsp salt
11 - ½ tsp black pepper
12 - ½ tsp ground nutmeg (optional)
→ Topping
13 - 1½ cups crispy fried onions (store-bought or homemade)
# How to Make It:
01 - Set the oven temperature to 350°F.
02 - Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender but still bright green. Drain and rinse under cold water immediately to halt cooking. Set aside.
03 - In a large skillet over medium heat, melt butter. Add mushrooms and cook for 5-6 minutes until tender and browned. Incorporate onion and garlic; cook an additional 2-3 minutes until softened.
04 - Stir in flour and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Bring to a simmer and cook until sauce thickens, about 5 minutes. Season with salt, pepper, and nutmeg if using.
05 - Add the drained green beans to the skillet and toss to coat evenly in the sauce.
06 - Transfer mixture to a 2-quart baking dish. Sprinkle half of the crispy fried onions evenly on top.
07 - Bake for 25 minutes until the mixture bubbles.
08 - Remove from oven, top with the remaining fried onions, and bake for an additional 5-7 minutes until golden and crisp.
09 - Allow to cool for 5 minutes before serving.
