Instructions

1. 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. 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. 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. 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. 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. 6

   Transfer the green bean mixture to a 9x13-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. 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: 9x13 Baking Dish · Stainless Steel Whisk (Amazon, affiliate links)