In a large pan, heat olive oil over medium high heat. Add the onion and peppers and sauté until tender, about 5 minutes. Stir in the beans, cilantro, lime juice, and taco seasoning. Cook until heated and season with salt and pepper, to taste.
Place bean filling inside of taco shells that have been heated according to package directions. Top the tacos with desired toppings. We like to use shredded cheese, lettuce, tomatoes, avocado, Greek yogurt and cilantro. Serve immediately.
Note-these tacos are also good with flour or corn tortillas!