Whisk olive oil, soy sauce, lime juice, garlic, chili powder, cumin, salt, and pepper in a bowl
Place the flank steak in a large resealable plastic bag or an airtight container and pour the marinade over it. Shake to evenly coat the steak
Place the mixture in the fridge for at least 30 minutes or overnight to give it time to absorb the marinade
Preheat your grill to medium-high heat
Remove the marinade and place the steaks on a rack to let any excess drip
Grill the steaks for about 5 minutes on each side or until preferred doneness is reached
Let rest before slicing thinly against the grain
Warm tortillas on the grill or microwave, then add sliced steak and toppings of your choice
Serve and enjoy!