marinade the beef with 6 tblsp soy sauce, 4 tblsp hoisin sauce, 1 tblsp garlic paste, 1 tblsp chili paste, 1 tsp grated ginger, 1 tsp sugar, 2 tblsp sesame oil, 1 tblsp rice starch, mix well, cover, let marinade overnight – the salt in the sauce will break down the fibers of the protein, thereby tenderize it