In a large bowl or zip-top bag, combine olive oil, lime juice, minced garlic, cumin, chili powder, smoked paprika, salt, and black pepper. Add the steak to the marinade, ensuring it’s fully coated. Let marinate in the refrigerator for at least 30 minutes, or up to 8 hours.

Preheat the grill to medium-high heat. Oil the grill grates to prevent sticking.

Remove the steak from the marinade and let it come to room temperature. Grill the steak for 4-6 minutes on each side, or until it reaches your preferred level of doneness. Use a meat thermometer to check internal temperature: 130°F for medium-rare.

While the steak is resting, grill the bell peppers and onions in a grill basket or directly on the grates for 8-10 minutes, turning occasionally, until charred and tender.

Slice the steak thinly against the grain, and warm the tortillas on the grill or in a dry skillet.

Assemble the fajitas by placing the sliced steak and grilled vegetables onto the tortillas. Add your desired toppings like avocado, salsa, sour cream, or shredded cheese.