In a small bowl, combine the chili powder, cumin, garlic powder, onion powder, smoked paprika, salt, and pepper to create a spice blend.

Rub the spice blend evenly over the flank steak. Allow it to marinate for at least 30 minutes, or up to overnight in the refrigerator for more flavor.

Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the marinated flank steak to the skillet and sear for about 4–5 minutes on each side, or until the steak reaches your desired level of doneness. Remove the steak from the skillet and let it rest for 5 minutes.

In the same skillet, add the remaining tablespoon of olive oil. Add the sliced bell pepper and onion. Sauté for about 5–7 minutes, or until the vegetables are tender.

While the vegetables are cooking, slice the rested steak against the grain into thin strips.

Return the sliced steak to the skillet with the sautéed vegetables. Toss everything together to heat through, about 1–2 minutes.

Warm the flour tortillas in a dry skillet or microwave.

To serve, place a generous portion of the steak and vegetable mixture onto each tortilla. Add any optional toppings you desire, such as sour cream, guacamole, salsa, shredded cheese, or cilantro.

Roll up the tortillas and enjoy your homemade steak fajitas!