Preheat oven to 325 degrees.

Reserve 2 Tablespoons each of the onions and tomatoes; set aside.

Cook bacon until crisp. Reserve 1 Tablespoon of bacon drippings to cook

mushrooms. Saute mushrooms about 2 minutes, or until tender. Remove from

heat. Chop bacon. Add to mushrooms along with the onions and tomatoes;

mix well.

Beat eggs and sour cream with a whisk until well blended. Pour into a

greased 13x9-inch baking dish. Top with bacon mixture and cheeses.

Bake 30 minutes or until center is set. Sprinkle with reserve onions and

tomatoes. Let stand 5 minutes before cutting into pieces to serve.