Whisk together the olive oil, vinegar, minced garlic, cumin, and paprika in a shallow bowl or glass dish.
Add the beef strips to the marinade, tossing to coat them thoroughly, and let them sit at room temperature for at least 1 hour.
Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
Sauté the diced onion and bell pepper until they are tender, then remove them from the pan and set aside on a plate.
Add the remaining tablespoon of oil to the same pan and sear the beef strips until they are browned and cooked to your preference.
Return the cooked vegetables to the pan along with the cilantro and lime juice, tossing everything together for about 1 minute to combine the flavors.
Season the mixture with salt and pepper to taste, then remove from the heat.
Spoon the beef and vegetable mixture into the warm flour tortillas and serve immediately with lime wedges on the side.