Slice the tofu into 1cm thick pieces.
Julienne the onion and bell pepper.
Heat olive oil in a pan and sauté the onion and bell pepper.
Add the tofu to the pan and grill until golden brown on both sides.
Layer the tofu in an oven-safe dish and top with the sautéed vegetables.
Pour tomato sauce over and sprinkle mozzarella cheese on top.
Bake in a preheated oven at 180°C for 15 minutes.