Rinse the pork belly thoroughly, then boil for 10 minutes. Remove and let drain. Prepare a dipping sauce by mixing the fish sauce, sugar, hot sauce, 1 teaspoon chili sauce, 1 tablespoon water, and add sliced chili peppers if you like it spicy.

Crush the garlic and shallots, then rub them onto the pork and let marinate for about 10 minutes. Wipe off the garlic and shallots from the pork to prevent burning during frying. Add oil to a pan, then mix in 1 teaspoon cornstarch to help prevent splattering. Fry each piece of pork until both sides are golden. Stand the pieces up to crisp the skin.

Pour out most of the oil from the pan, then sauté garlic and shallots in the same pan until fragrant. Pour in the prepared sauce and simmer on low heat. Add the pork back in and cook until the sauce is absorbed and reduced.

Arrange the pork on a plate, garnish with salad greens and cucumber, and serve with rice. The pork is flavorful, savory, and sweet, with crispy skin.