Cut the tofu into bite-sized pieces.
Finely chop the onion and bell pepper.
Heat olive oil in a pan and sauté the onion and bell pepper.
Add the tofu and lightly stir-fry.
Add the tomato sauce and mix well.
Transfer to an oven-safe dish and top with cheese.
Bake in a preheated oven at 180°C (356°F) for 10 minutes.