Preheat oven to 400°F (200°C). Line a sheet pan with parchment paper and spray with cooking spray.

In a large bowl, combine the ground chicken, cottage cheese, egg, Parmesan, Italian seasoning, salt, and pepper. Mix well until evenly combined. If making multiple pizzas, divide the mixture evenly among them.

Spread the chicken mixture onto the prepared sheet pan in a ¼-inch (0.6 cm) thick circle, shaping it like a pizza crust.

Bake for about 30 minutes, or until the crust is firm and golden.

Remove the crust from the oven and spread the barbecue sauce evenly over the top, leaving a small border around the edges. Sprinkle the mozzarella and red onion over the sauce.

Return the pizza to the oven and bake for about 10 minutes, until the cheese is melted.

Let the pizza cool for a few minutes before slicing each pizza into 4 slices. Serve.