1Heat oven to 350°F. Spray 9-inch glass pie plate with cooking spray. Sprinkle 1 cup of the cheese and the onions in pie plate.
2In medium bowl, stir Bisquick mix, milk and eggs with wire whisk or fork until well blended. Pour into pie plate.
3Bake 30 to 35 minutes or until knife inserted in center comes out clean. Sprinkle with remaining 1/4 cup cheese; bake 3 to 5 minutes longer or until melted. Let stand 5 minutes before serving.
4In small bowl, mix salsa and preserves. Serve omelet with salsa.