Mix together spices in small bowl. Wipe beef dry, rub with olive oil, and spices. Wrap in plastic wrap, refrigerate.
Marinated overnight or for a few hours before cooking. Remove & bring to room temp 1/2 hour before grilling.
Slice veggies up & place in large bowl, sprinkle with olive oil & preferred spices, toss. Place on baking sheet appropriate for grilling.
Grill veggies before or during fajatia grilling. Grill skirt steak on each side for about 20 min. on med. high grill heat. This is best eaten medium rare. The longer you cook it, the tougher it gets.
Let rest for 20 min., then slice thinly against the grain. Since the grain run across the skirt steak you need to slice it crossways in about 3" strips, then go back & slice the strips against the grain. Place on warm tortilla, top with cheese & grilled veggies. Garnish with salsa, sour creme or pico de gallo.