1/2 cup light soy sauce
1/4 cup porter
1/4 cup brown sugar
2 teaspooons freshly ground black pepper
1/2 teaspoon red pepper flakes, coarsely ground in a spice mill or coffee grinder
1 1/2 teaspoons onion powder
1 teaspoon Chinese five-spice powder
3 cloves garlic, minced
4 pounds beef, fat removed and sliced along the grain, in long strips
Combine all ingredients except the beef in a large bowl and mix thoroughly. Rub the beef well with the mixture and layer in a deep bowl or crock, covering with whatever sauce is left over. Place a plate and a heavy weight on top of the beef and refrigerate overnight.
Drain the beef and place the strips on racks in a smoker, on the barbecue or in the oven. Cook on lowest possible heat for 3-4 hours until nearly dry. Remove strips and let stand in a warm place until completely dry.