Cut the thinly sliced pork belly, onion, and perilla leaves into bite-sized pieces.
Stir-fry the pork belly in a pan without oil.
When the pork belly is about half cooked, add the onion and stir-fry together.
Once the onion turns translucent, season with soy sauce, sugar, and minced garlic.
Add the perilla leaves and stir-fry for a bit longer.
Serve the stir-fried ingredients over rice to finish.