1 c. flour
1/2 tsp. baking soda
1/2 tsp. salt
1/3 c. grated Parmesan cheese
2 1/2 c. milk
4 eggs
1/2 c. chopped onions
1/2 c. chopped mushrooms

Saute onions and mushrooms, then set aside to cool.

Combine flour, baking soda, salt and grated cheese. Gradually stir in milk, stirring until well blended and smooth. Add eggs, one at a time. Stir in sauteed onions and mushrooms.

Pour into very hot greased pan (10 1/2 inch cast iron skillet). Bake at 500 degrees for 10 minutes, reduce to 450 degrees for 5 minutes, reduce again to 400 degrees for 5 to 10 minutes until done. Check by inserting knife in center. This omelet is a custard/popover type of omelet.