Depending on how many people you have over, here is a simple tip to follow, every 2 LB of flank steak gets you 4 servings.
Next, place and mix all these ingredients (for 4 servings) in a deep bowl: 4 tablespoons of English sauce, 2 tablespoons garlic, finely chopped, 2 tablespoons dried oregano, 1 tablespoon ground cumin, Juice of 1 lemon, 1 qt of beer, or the amount needed to cover the meat and Salt and pepper to taste.
Place the meat in a zippered bag and the liquid should cover the meat completely. Let it rest and marinate 6 to 8 hours minimum, or preferably overnight in the refrigerator so that the meat has time to soften.
Remove the meat from the refrigerator one hour before starting to grill so that the meat has time to reach room temperature.
Remove the flank steak from the marinade and place on the grill.
Serve, when ready and enjoy!