Cut the onion, bell pepper, and zucchini into bite-size pieces.
Season the thinly sliced pork belly with salt and pepper.
Add oil to a pan and stir-fry the pork belly.
When the meat is halfway cooked, add the prepared vegetables and continue stir-frying together.
Once the vegetables become translucent, place the stir-fried meat and vegetables over rice.
Top with mozzarella cheese, cover with a lid, and cook until the cheese melts.