6 large white onions, thinly sliced
1/3 cup extra-virgin olive oil
salt and freshly ground black pepper to taste cup
Beef stock

Place the onions in a heavy-bottomed pan with the oil over low heat. Season
with a little salt (use less than normal because the very slow cooking
enhances the taste of the salt). Add a grinding of pepper and cover.
Cook gently over low heat for at least 3 hours.
The onions must not burn, but should slowly melt.
Stir frequently, adding stock as necessary to keep the sauce moist. .
When cooked, the sauce should be creamy and golden