Add the skirt steak to a container filled with water and let soak in the refrigerator for about an hour, changing the water every 20 minutes.
In a food processor, combine olive oil, sherry, lemon juice, parsley, basil, oregano, garlic, and shallots. Blend but do not purée. Add salt, black pepper, and crushed red pepper.
Transfer sauce to a bowl. Add skirt steak (it should already have been soaked and pounded thin) and marinate for two to four hours.
Meanwhile, preheat oven to 350 degrees Fahrenheit. Heat a grill pan or grill, and grill skirt steak for six minutes on each side. Return meat to the sauce and bake for 15 minutes.