Add the steak to a large bowl with 2 tbsp olive oil, lime juice, garlic, chili powder, paprika, cumin, onion powder, salt, oregano, black pepper, optional chili flakes, and cilantro. Toss until evenly coated, cover, and refrigerate for 1–2 hours.
Mash the avocados to your desired consistency. Mix in the lime juice, cilantro, and salt. Cover and refrigerate until serving.
Combine the tomatoes, onion, jalapeño, cilantro, lime juice, and salt. Let sit for 15–20 minutes, then drain any excess liquid.
Heat a large skillet or cast-iron pan over high heat. Add some of the remaining olive oil, then cook the steak in a single layer in batches. Sear without moving for about 1 minute, then stir and cook for another 1–2 minutes, or until browned and cooked to your liking. Add more oil between batches as needed.
Warm or lightly char the corn tortillas in a dry skillet until soft with lightly toasted edges.
Spread guacamole onto each tortilla, top with the seared steak, and finish with a generous spoonful of pico de gallo. Serve immediately with fresh lime wedges.
