01 - Whisk together olive oil, lime juice, minced garlic, smoked paprika, cumin, chili powder, dried oregano, salt, and black pepper in a large bowl. Add flank steak and toss thoroughly to coat. Cover and refrigerate for at least 20 minutes, up to 2 hours for enhanced flavor penetration.
02 - Preheat grill or grill pan over high heat. Remove steak from marinade, allowing excess liquid to drip off.
03 - Grill steak for 4–5 minutes per side for medium-rare doneness, adjusting time to achieve preferred internal temperature. Transfer to cutting board, tent loosely with aluminum foil, and rest for 5 minutes.
04 - While steak rests, heat 1 tablespoon olive oil in large skillet over medium-high heat. Add sliced bell peppers and onion, season with salt and pepper, and sauté until tender-crisp with slight char, approximately 6–8 minutes.
05 - Heat tortillas on grill or in dry skillet for 30 seconds per side until pliable and warm.
06 - Slice rested steak thinly against the grain to ensure tenderness.
07 - Arrange grilled steak slices and sautéed vegetables on large platter. Serve accompanied by warmed tortillas, sliced avocado, sour cream, fresh salsa, chopped cilantro, and lime wedges.