The Best Fajita Marinade Yields: enough for a 2 lb skirt steak 4-5 large garlic cloves, crushed 1/4 cup freshly squeezed lime juice 2 tsp salt 1 tbsp chili powder 1/2 tsp red pepper flakes 1/2 cup balsamic or red wine vinegar 2 tbsp dark soy sauce 1/4 cup fresh cilantro, chopped roughly Directions: mix everything above together. Let beef marinade in the refrigerator for at least 4 hours and chicken for at least 2 hours. Then grill over charcoal for best results but it is also good in the broiler.