Marinate the flank steak in olive oil, chili powder, cumin, garlic powder, salt, and pepper for at least 30 minutes.

Preheat your grill or skillet over medium-high heat.

Cook the marinated steak for about 4-5 minutes on each side for medium-rare.

Remove the steak from the grill and let it rest for 5 minutes.

Sauté the sliced bell peppers and onions in the same skillet until tender.

Slice the rested steak against the grain into thin strips.

Warm the tortillas in a separate pan or microwave.

Assemble the fajitas by placing steak and sautéed vegetables on each tortilla.

Garnish with fresh cilantro and serve with lime wedges.