Combine the cilantro leaves, green chiles, lime juice, cumin, chili powder, red pepper flakes, and salt in a food processor or blender and process until smooth.
Spread the cilantro lime sauce over the prepared pizza crusts.
Add on the diced chicken, spreading out evenly over the pizza.
Top with an even layer mozzarella cheese.
Sprinkle diced onion over pizzas.
Bake in an oven that is heated as high as it will go (mine is 500 degrees) on a pre-heated pizza stone for about 10-12 minutes, until the cheese gets beautiful brown bubbles on it.