Inspired by the casserole of my youth, this Green Bean Casserole is reimagined with fresh green beans, roasted wild mushrooms, creamy béchamel sauce, and a crispy shallot topping.
Preheat oven to 425 degrees. Spread sliced mushrooms and thyme onto the baking sheet, drizzle with olive oil, and sprinkle with salt and pepper. Roast about 15 minutes.