Sprinkle chicken with chilli powder. Lightly spray a large non-stick frying pan with oil and heat over high heat.
Cook chicken for 3–4 minutes each side or until golden and cooked through. Remove from pan, set aside to cool, then slice thinly.
Spread 1 tablespoon of tomato paste over each tortilla. Top each tortilla with beans, chicken, shallots and cheese. Place pizzas on 2 large baking trays and bake for 8–10 minutes or until bases are crisp and golden.