Cut the tofu into bite-sized pieces.
Slice the onion and bell pepper thinly.
Add olive oil to a pan and sauté the onion and bell pepper.
Add the tofu and grill both sides until lightly browned.
Place the grilled tofu and vegetables in a gratin dish.
Pour tomato sauce over them, then add mozzarella cheese and parmesan cheese on top.
Bake in the oven at 200°C for 10 minutes until the cheese melts.