Cut the soft tofu into bite-sized pieces.
Finely chop the onion and bell pepper.
Preheat the oven to 180°C (356°F).
In a pan, add olive oil and sauté the chopped onion, bell pepper, and minced garlic.
Add the tomato sauce and bring to a simmer.
Place the tofu in an oven-safe dish and pour the sauce over it.
Evenly sprinkle mozzarella cheese on top.
Bake in the preheated oven for 10 minutes until the cheese is melted and bubbly.