Thai Stir fried Beef with Mint (nue Gra Pao)

Serves 4 to 6. Slice the beef across the grain into strips 1/4 inch thick and 2 to 3 inches long. Set aside. Pound or grind the chilies, garlic, and onion to a coarse paste in a mortar or blender. If you use a blender you may need to add the oil to aid in grinding. Heat a wok, add the oil, and swirl it over the surface of the pan. (Do not add more oil if you have ground the chilies, onion, and garlic in oil.) Add the paste from Step 2 and stir-fry until it is light golden. Add the beef and stir-fry until it is a uniform tan color, but do not overcook it. Add the fish sauce, sugar, water, and mint (or basil) leaves. More water may be added if the sauce is too dry. There should be about 1/2 to 3/4 cup sauce, depending on how much water you added. Arrange a single layer of lettuce leaves in a serving bowl and put the beef mixture over them. Serve the beef immediately or keep it warm while preparing other dishes. Serve with rice.