In a bowl, mix olive oil, lime juice, garlic powder, cumin, chili powder, salt, and black pepper. Add the skirt steak and coat well. Cover and marinate in the refrigerator for at least 30 minutes.

Prepare Vegetables

While the steak is marinating, slice the bell peppers and onion into thin strips.

Cooking

Cook the Steak

Preheat a grill or skillet over medium-high heat. Remove the steak from the marinade and grill for about 3-4 minutes per side for medium-rare, or until desired doneness is achieved. Let rest for 5 minutes before slicing.

Sauté the Vegetables

In the same skillet, add the sliced bell peppers and onion. Sauté for about 5-7 minutes until tender.

Assemble Fajitas

Slice the rested steak against the grain and serve with sautéed vegetables, tortillas, guacamole, pico de gallo, and sour cream.