In a large skillet, brown the sausage and cook the pepper, onion, and mushrooms together. The vegetables will become tender as the meat cooks. Add the crushed tomatoes, herbes de Provence, and red wine. Simmer for ten minutes.
Meanwhile in a small saucepan, melt the butter. Add the flour and whisk until blended and bubbly. Whisk in the milk, garlic powder, salt, and pepper. Whisk until smooth, over medium heat until the sauce thickens. Remove from heat.
Grease a 9x13-inch pan. Spread 1 ½ cups of the meat sauce in the bottom of the pan. Sprinkle 1 cup of mozzarella cheese over the sauce.
Lay 3 noodles across the cheese. Spread 1 cup of meat sauce over the noodles, followed by 1 cup of cheese and another 3 noodles.
Pour the white sauce over the noodles in the pan. Top with 1 cup mozzarella and the remaining 3 noodles.
Spread the rest of the meat sauce over the noodles. Top with the remaining cheese.
Bake in a preheated 400° oven for 30 minutes. Allow to rest 10 minutes before serving.
Notes
To Make-Ahead: Refrigerate the unbaked lasagna for up to 1 day or chill it completely and freeze for 2 to 3 months. To serve: Thaw completely in the refrigerator before following baking instructions. Add 5 to 10 minutes to allow for a cold pan.