French Sweet Onion Casserole

From Southern Living cookbook. I love onions this is so good.

• Ready In: 1 hr 10 mins
• Serves: 6

Ingredients

• 3  medium sweet onions
• 2  tablespoons butter
• 8  ounces  fresh  sliced mushrooms
• 2  cups  shredded swiss cheese, divided
• 1 (10 3/4ounce) can  mushroom soup
• 1 (5 ounce) can evaporated milk
• 2  teaspoons soy sauce
• 6  slices  French bread (1/2-inch thick)
• 1⁄4 cup  chopped fresh parsley

Directions

1. Slice onions crosswise cut each of the slices in half.
2. Melt butter in large skillet,medium high heat cook onions and mushrooms until tender.
3. Spoon mixture into a lightly greased 2-QT baking dish.
4. Sprinkle with 1 cup cheese.
5. Combine soup, milk, and soy sauce; pour over cheese.
6. Top with bread slices and sprinkle with remaining 1 cup cheese and parsley.
7. Cover and refrigerate 4-8 hours.
8. Remove and let stand 30 minutes.
9. Bake covered 375°F for 30 minutes,uncover and bake 15-20 more minutes.
10. Let stand 5 minutes before serving.