4 large onions, thickly sliced 1/2-inch
1 stick butter
2/3 c. chicken broth
1/3 c. dry sherry
2 tbsp. flour
1 1/2 c. soft bread crumbs
1/2 c. grated sharp Cheddar cheese
2 tbsp. grated Parmesan

Sauté sweet onions in butter until transparent. Add chicken broth, sherry and flour. Cook and stir. When slightly thickened, transfer to medium casserole. Top with bread crumbs and both cheeses.

Bake at 350°F for 20 to 30 minutes or until lightly browned and bubbly.