01 - Combine sliced beef, olive oil, garlic, chili powder, cumin, smoked paprika, oregano, salt, and black pepper in a large bowl. Toss to coat and set aside to marinate for 10 minutes or up to 1 hour for enhanced flavor.
02 - Heat a large skillet over medium-high heat. Add the marinated beef in a single layer and sear for 2 to 3 minutes per side until browned and just cooked through. Remove from skillet and set aside.
03 - In the same skillet, add a drizzle of olive oil if necessary. Sauté sliced bell peppers and red onion for 5 to 7 minutes, stirring occasionally, until softened and slightly charred.
04 - Return the beef to the skillet with the vegetables. Pour in the lime juice and toss to combine. Cook for 1 to 2 minutes to warm everything evenly.
05 - Serve immediately with warm corn or flour tortillas and desired toppings such as sour cream, chopped cilantro, lime wedges, and sliced avocado.