Preheat the oven: Set to 425°F (220°C). Place a baking sheet inside to heat up; this helps crisp the flatbread.
Season the chicken: Toss the sliced chicken with taco seasoning, a pinch of salt, and a drizzle of olive oil.
If using tomato paste, rub it in now.
Cook the chicken: Heat a skillet over medium-high with the remaining oil. Cook chicken 4–6 minutes, stirring, until browned and cooked through. Add 2–3 tablespoons broth or water to loosen spices and coat the chicken.
Remove from heat.
Warm the flatbread: Place flatbreads on the hot baking sheet. Bake 3–4 minutes until lightly toasted and just starting to crisp.
Add the base layer: Sprinkle half the cheese on the toasted flatbreads. This creates a melty “glue” for toppings.
Top with chicken and veggies: Scatter the cooked chicken, bell pepper, red onion, corn, and black beans evenly over both flatbreads.
Finish with cheese: Sprinkle the remaining cheese on top.
Return to the oven for 6–8 minutes, until the cheese is melted and edges are crisp.
Mix the sauce: Stir Greek yogurt, lime juice, salt, and chili powder or smoked paprika in a small bowl until smooth.
Top and serve: Remove flatbreads from the oven. Add cherry tomatoes, avocado, and cilantro. Drizzle with the yogurt sauce.
Slice and serve with lime wedges.