SAUCE: Zest and juice 1 lime to get 3 tablespoons juice and 1/2 teaspoon zest. Add the juice and zest to a blender or mini food processor along with the minced garlic, cilantro, 1/2 of the seeded jalapeño (add more of the jalapeño for a spicier sauce; add slowly if you like less heat), mayo and sour cream. Add salt and pepper to taste and blend or pulse until smooth. Refrigerate until ready to serve.
BBQ CHICKEN: Pull the chicken from the bones and shred or chop. Add the BBQ sauce and mix to combine. If the chicken is cold, warm it through in a skillet over low heat.
VEGGIES: In a large bowl, combine the chopped cherry tomatoes, diced red onion, drained and rinsed black beans, and corn.
CABBAGE: Remove 1/2 a cup of the cilantro-lime sauce, and toss it with the shredded green cabbage to combine. Set aside.
TORTILLAS: Spray both sides of the tortillas with olive oil cooking spray and "grill" tortillas on stovetop over the open flame until slightly charred. Alternatively warm (covered with a damp paper towel) in the microwave. After tortillas have been warmed or charred, quickly fold them in half so they will fold easily when assembled.
ASSEMBLE: To the tortilla, add the dressed cabbage, a few spoonfuls of BBQ chicken, and a few spoonfuls of the veggies. If desired, add avocado and fresh cilantro to each taco. Drizzle with extra cilantro-lime sauce and enjoy!