Preheat oven to 375F. Grease a 9-inch quiche pan, pie pan or square cake pan. Saute onion in butter until transparent. Combine remaining ingredients, except mushrooms, in mixing bowl. Add onion. Beat on medium speed of electric mixer about 2 minutes. Stir in mushrooms. Pour onto prepared pan. Bake on bottom rack of oven 35 minutes or until knife inserted in center comes out clean. Allow to stand at least 5 minutes before cutting into wedges or squares.
Makes 6 to 8 servings or 24 appetizers.
Casseroles - Quiches
Cajun Country -- New Iberia, Louisiana