Wash and clean the tripe well then boil in a large pot over medium heat for about 1 hour until tender. In another pot, cook the lungs and heart. The water will become cloudy and scum will come to the surface. Let it boil for about 15 minutes then carefully dump out the water and replace with clean water. Bring the water back to a boil and cook the heart and lungs over medium heat for about 30 more minutes. Remove them from the pot to cool then chop the heart and liver into small dice. Saute the garlic, onions and tomatoes in vegetable oil. Add the chopped lungs and heart. Add the daikon, peppers and fish sauce and cook for about 5 minutes. Add the tripe then add the vinegar and water and cook until meat is tender and the sauce has reduced, about 15-20 minutes . Season with salt and pepper.