Combine olive oil, cumin, chili powder, smoked paprika, garlic powder, salt, and pepper in a bowl to make the marinade.
Rub the marinade evenly onto the steak and let it rest for at least 30 minutes or overnight for deeper flavor.
Heat a skillet or grill over medium-high heat and cook the steak 4–5 minutes per side until desired doneness.
Allow the steak to rest for 5 minutes, then slice thinly against the grain.
Warm the beans, cooked rice, and tortillas before assembling the burritos.
Lay a tortilla flat and layer rice, beans, steak, cheese, salsa, sour cream, and optional cilantro and onions.
Fold in the sides tightly, roll the burrito, slice in half, and serve warm.