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're worried about the 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, add in the chopped cherry tomatoes, diced red onion, drained and rinsed black beans, and corn. Toss to combine.
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!