Toss broccoli, cauliflower, kohlrabi, and mushrooms in olive oil and season with salt and pepper. Spread on a baking sheet and roast for 20 minutes until vegetables begin to brown and soften.
Meanwhile, cook sausage in a skillet over medium high heat until browned. Drain and set aside.
In a small saucepan bring chicken stock and milk to a boil. Reduce to a simmer and whisk in flour to form a thick sauce. Add Gruyere whisking constantly until smooth and fully combined. If the sauce seems too thick, add a little bit more milk.
Stir together roasted vegetables, sausage and cheese sauce. Pour into a greased casserole dish.
Melt butter in a small skillet. Add panko breadcrumbs and stir constantly until browned. Top casserole with toasted breadcrumbs.
Bake casserole, uncovered for 25 minutes until bubbly.
Cheesy Sausage and Roasted Vegetable Casserole
Amount Per Serving (1 g)
Calories 242Calories from Fat 135
% Daily Value*
* Percent Daily Values are based on a 2000 calorie diet.