Rinse the pork belly and slice it thinly. Marinate with fish sauce, sugar, seasoning powder, and black pepper until well absorbed. Heat a pan and sauté chopped onion and garlic until fragrant, then add the pork and stir until the meat firms up.

Lower the heat and continue stirring the pork. When the fat has rendered and the meat becomes tender, turn off the heat. Add more black pepper and chopped green onions. Serve hot with steamed rice and cucumber for a delicious meal.