Prepare all the ingredients.

In a large pot, bring 4 quarts (4 liters) of water to a boil with salt and a few drops of olive oil. Cover and heat on high to cook the pasta.

Once the water is boiling, add the pasta. Cook for 6 minutes (2 minutes less than the package instructions). Don’t overcook—the pasta should be slightly firm since it will bake in the oven.

In a medium saucepan, heat the olive oil. Add the onion, carrot, and garlic and sauté until softened.

Add the chopped mushrooms and cook for about 3 minutes. Pour in the wine and season with salt and pepper.

Add the tomato sauce and sugar. Stir in the bouillon cube and thyme. Simmer for about 20 minutes. Taste and add more salt and pepper if needed.

In a baking dish, layer half the pasta, sprinkle with cheese, then add the mushroom filling. Top with the remaining pasta.

Finally, make the béchamel. In a large saucepan, melt the butter. Lower the heat and gradually add the flour, stirring for 1–2 minutes to cook it slightly. Add the warm water with bouillon and the milk (all together), whisking constantly.