By Edgar Steele,
NFCA Chef Spokesman
Melt the butter in a small sauté pan over very low heat. Add the onions and bay leaf and allow them to cook, stirring occasionally, until the onions are slightly golden in color, about 30 minutes. If browning occurs at the bottom of the pan before the onions are finished cooking, try adjusting the heat to a lower flame or you may add a few drops of water to the pan and scrape the bottom of the pan to lift the browning areas.
Stir in the balsamic vinegar and Worcestershire sauce, and adjust the heat to medium. Allow the onions to simmer until the liquid is almost completely reduced. Season to taste with salt and reserve hot.