In a large bowl or zip-top bag, combine olive oil, orange juice, lime juice, garlic, cumin, chili powder, paprika, salt, and pepper.
Add the steak and coat it completely with the marinade. Cover and refrigerate for at least 2 hours or overnight for maximum flavor.
Preheat a grill or grill pan to high heat.
Remove the steak from the marinade and let excess marinade drip off.
Grill the steak for 4 to 6 minutes per side, depending on thickness and desired doneness.
Transfer the steak to a cutting board and allow it to rest for 10 minutes.
Warm the corn tortillas on the grill or in a dry skillet until soft and slightly charred.
Slice the steak thinly against the grain into bite-sized strips.
Fill each tortilla with carne asada.
Top with diced onions, chopped cilantro, and your favorite toppings.
Serve immediately with fresh lime wedges.