Cut the tofu into bite-sized pieces.
Julienne the onion and bell pepper.
Add olive oil to a pan and sauté the onion and bell pepper.
Place the sautéed vegetables and tofu in an oven-safe dish.
Pour tomato sauce evenly over the mixture.
Top with mozzarella cheese.
Bake in a preheated oven at 180°C for 15 minutes.