Scoop the soft tofu into small pieces with a spoon and set aside.
Chop the onion and bell pepper into small pieces.
Cut the bacon into bite-sized pieces.
Heat olive oil in a pan and sauté the bacon, onion, and bell pepper.
Add tomato sauce and let it simmer for 2-3 minutes.
Add the soft tofu and gently mix until well combined.
Transfer the mixture to a gratin dish and top with mozzarella cheese.
Bake in the oven at 200°C (392°F) for 10 minutes until the cheese is golden brown.