Finely chop the onion and green onion.
Heat olive oil in a pan and sauté the onion and green onion.
Add minced pork and sauté together.
Pour in tomato sauce and bring to a simmer.
Add soft tofu and gently mix.
Transfer to a gratin dish and top with mozzarella cheese.
Bake in a 200°C oven for 10 minutes.