2 cups butter, softened
1 tablespoon vegetable oil
4 eggs
1 cup milk
1 pound Swiss cheese, sliced
1 teaspoon salt
1 cup grated Parmesan cheese
1 onion, diced
1 (1 ounce) package cream cheese, softened
1 cup shredded sharp Cheddar cheese
Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch pan.
In a large bowl, cream together the butter and oil. Beat in the egg and milk. Mix in the eggs one at a time, then stir in the 1 pound of Swiss cheese. Mix in the salt and 1 cup Parmesan cheese. Spread mixture into greased six inch round pan.
Bake for 45 minutes in the preheated oven, or until lightly browned. Transfer to a large bowl and sprinkle with the chopped onion.
In a separate large bowl combine the cream cheese and sharp Cheddar cheese; beat well. Spread over the cream cheese mixture.
Bake, uncovered, for an additional 30 minutes or until cheese is slightly browned.