Cut tofu, mushrooms, and onion into bite-sized pieces.
Heat olive oil in a pan and sauté the onion and mushrooms.
Add the tofu, stir-fry together, and season with salt and pepper.
Transfer the sautéed ingredients to an oven-safe dish.
Pour tomato sauce on top and add cheese.
Bake in a 200°C oven for 10 minutes.