1 lb pork (cut in small thin pieces across the grain)
1/2 cup soy sauce
1/4 vinegar (Chinese if possible)
1 tblsp sugar
5 tsp corn starch
1-2 Tblsp vegetable oil
1 small can pineapple (drained)
1-2 cloves garlic (minced)

Mix together 1/3 cup soy sauce, 1/8 tsp vinegar, 1/2 tblsp sugar, and enough corn starch, about 2 tsp, to thicken the sauce. When all is well mixed, pour over the meat, mix well and then let sit for about 1/2 hour.

While the meat is marinating, prepare the sauce using the rest of the soy sauce, vinegar and sugar. Mix this together with 3 tsp corn starch, a pinch of salt and enough water to give 3/4 cup of sauce.

Heat oil of medium-high heat until hot. Then add the meat piece by piece, frying for a short time until the meat is cooked through, about 2 minutes. Remove and then set aside. Put more oil in the pan and heat. To the hot oil then add the meat and pineapple pieces. Stir-fry the mixture for 10-20 seconds then pour on the sauce. Stir well. Continue cooking until the sauce reaches the desired thickness then add the garlic pieces. Continue cooking for about 15-30 seconds then remove. Serve hot or slightly cooled.