1Heat oven to 400°F. Spray 9-inch glass pie plate with cooking spray. In 10-inch skillet, cook sausage over medium-high heat, stirring occasionally, until no longer pink; drain. Sprinkle sausage, chicken, spinach, onions and 1/2 cup of the cheese in pie plate.
2In medium bowl, stir remaining ingredients until blended. Pour into pie plate.
3Bake uncovered 30 to 35 minutes or until knife inserted in center comes out clean. Sprinkle with remaining 1/2 cup cheese. Bake about 2 minutes longer or until cheese is melted. Let stand 5 minutes before serving.