In a large pot combine the first 8 ingredients: beef, vinegar, garlic, soy sauce, bay leaves, peppercorns, ground pepper and sugar.
Let stand for 2 hours (traditional method is room temperature, I put in in the refrigerator).
Bring mixture to a boil then simmer about an hour or until the meat is tender.
Heat oil in a large skillet. Use a slotted spoon to spoon out garlic from beef mixture. Add garlic to skillet and cook until brown. Use slotted spoon to add the beef to the skillet with garlic and continue to cook, stirring, until it is browned on all sides.
Add salt or patis to taste and the coconut milk. Add the sauce from the pot that the beef simmered inches Cook for 5 more minutes.