Flat iron steak is a tender cut from the chuck top blade roast. If flat iron steak is unavailable, you can use flank steak, skirt steak, or chuck steak - but you will have to adjust the cooking time to a time that is appropriate for their thickness. Steak should marinate overnight in the refrigerator. The sauces can all be made the night before as well, cover and refrigerate. Pico De Gallo is Spanish for "rooster's beak". It is traditionally a relish chopped ingredients. The version below is similar to what you would find in Mexico and makes about 1 1/2 cups. Guacamole makes about 1 cup. Cilantro Cream Sauce makes about 1/2 cup. The Fajita Marinade makes about 2 cups.