Heat the olive oil in a skillet over medium heat. Cook the onion and garlic in the hot oil until fragrant, about 5 minutes. Mix the pork into the onion and garlic; cook until no longer pink, about 5 minutes. Stir the prawns into the mixture and cook until no longer translucent, about 5 minutes more. Add the tomatoes; season with salt and pepper. Continue cooking until the tomatoes soften, about 5 minutes. Stir the bitter melon through the mixture and cook until the melon is tender, about 5 minutes. Serve hot.
