Ingredient

• 1½ pounds green beans, trimmed and halved
• 2 tablespoons extra-virgin olive oil
• 16 ounces cremini mushrooms, sliced
• 2 tablespoons tamari
• 4 garlic cloves, minced
• 2 tablespoons fresh thyme leaves
• ¼ cup all-purpose flour
• 3 cups milk, any kind
• 1½ teaspoons Dijon mustard
• ½ cup grated Parmesan cheese, plus more for sprinkling
• ¼ teaspoon freshly ground black pepper
• 1½ cups French fried onions, or homemade Crispy Baked Onions (see recipe notes)

Direction

1. Preheat the oven to 400°F. Lightly grease a 9x13-inch baking dish.
2. Bring a large pot of salted water to a boil and set a large bowl of ice water nearby. Drop the green beans into the boiling water and blanch for 4 minutes. Drain, and immediately immerse in the ice water to stop the cooking process. Drain, and transfer to a towel to dry.
3. Heat the olive oil in a large skillet, add the mushrooms, and cook until soft, 8 to 10 minutes. Stir in the tamari, garlic, and thyme. Sprinkle the flour over the mushrooms and stir again. Add the milk and mustard and stir to combine. Simmer until thickened, whisking often, 15 to 20 minutes. Stir in the Parmesan cheese and pepper.
4. Spread ⅓ of the sauce into the baking dish. Layer with green beans and top with the remaining sauce. Sprinkle the onions on top and bake, covered, for 10 minutes. Uncover and bake 10 more minutes. If the onions start to brown too much, cover the dish for the remainder of the baking time. Garnish with sprinkles of Parmesan, if desired. Serve hot.