4 good size bowls: Melt butter and olive oil in large heavy pan. cook onions in over medium low heat until very carmelised. This step takes the longest, upt to 2 hrs to get all onions cooked down, sweet, and dark. Deglase pan with stock, add brandy/ wine salt and pepper. Toast bread, then top with cheese, and under broiler melt to bubbly and brown. Serve soup in bowls, with bread floated on top.
Simple soup, delicious and simple.