Cut the steak into 1/2" strips. Combine the soy sauce, beef bouillon, mashed garlic and ginger. Pour this marinade over the steak strips. Cover. Marinate, refrigerated, at least 2 hours (up to 12 hours). Drain the meat. Discard the garlic. Reserve 1/2 cup of the marinade. Dry the meat strips on toweling. Brown the meat in the vegetable oil in a large skillet. Heat the reserved marinade in a separate pan. Add the reserved marinade. Add the BOILING water. Cover. Simmer about 45 minutes. Add the green bell pepper strips and the sliced water chestnuts. Simmer until the meat is tender. Mix the cornstarch in the second measure of water until smooth. Gradually stir this mixture into the meat mixture. Continue stirring until the gravy thickens. Serve over boiled white rice.