Cut the pork ribs into individual pieces.
Place them into a large pot, cover with water, and bring to a boil.
Reduce the heat and simmer for 20–30 minutes until slightly tender.
Drain well.
Heat the vegetable oil in a large skillet or wok over medium-high heat.
Add the cooked ribs.
Season with salt, soy sauce, dark soy sauce, oyster sauce, black pepper, and chili flakes.
Stir well until the ribs are evenly coated.
Add the sliced onion.
Cover with a lid.
Reduce to low heat and cook for 30 minutes, stirring occasionally.
Add the chopped garlic.
Cook for another 2–3 minutes until fragrant.
Remove from heat.
Add chopped cilantro and green onions.
Mix everything together and serve immediately.