Put this together in the morning so can have a wonderfully different side dish that evening. Delicious companion with any beef, particularly steaks or roasts.
- Cut onion in half from top to bottom, then with cut side down, slice moderately thinly.
- Melt butter in a large skillet over medium-high heat, cook onions and mushrooms, stirring constantly until tender.
- Spoon onion/mushroom mixture into lightly greased 2 quart baking dish.
- Sprinkle with 1 cup of cheese.
- Combine soup, milk and worcestershire sauce and pour over cheese.
- Top with bread slices and sprinkle with remaining cheese.
- Cover and refrigerate for 4 to 8 hours.
- Remove baking dish from refrigerator and let stand at room temperature for 30 minutes.
- Bake covered at 375º for 30 minutes.
- Uncover and bake 15 to 20 additional minutes or until thoroughly heated.
- Let stand 5 minutes before serving.
Absolutely sinful...I plan to keep this recipe the same as it is for company. The next time I make it for my family, I want to lighten it up by using less butter and cheese and substituting evaporated milk for the cream.