Cut the soft tofu into bite-sized pieces.
Finely chop the onion, bell pepper, and ham.
Heat olive oil in a pan and sauté the onion, ham, and bell pepper.
Add tomato sauce and simmer briefly.
Place the soft tofu in an oven-safe dish and top with the sautéed ingredients and sauce.
Evenly sprinkle mozzarella cheese on top.
Bake in the oven at 200°C (392°F) for 10 minutes.