Heat the oven to 450°F. Place the tortillas onto 2 baking sheets. Spray the tortillas with the cooking spray. Bake for 5 minutes or until the tortillas are golden.
Spread about 1/4 cup picante sauce onto each tortilla to within 1/2 inch of the edge. Top with the chicken, cheese and onions.
Bake for 5 minutes or until the cheese is melted.