Slice sirloin into 3- to 4-inch pieces and put them inside a gallon sized zippered plastic storage bag.
Mix together remaining ingredients in a small mixing bowl. Pour marinade over sirloin in storage bag and seal. Move bag around to distribute marinade evenly. Refrigerate for 4 to 24 hours.
Remove steak from marinade and grill for 5 to 7 minutes each side. Discard remaining marinade.