Ingredients
Method
- Melt the butter with olive oil in a Dutch oven and add the onions, salt and sugar.
- Cook over medium-low heat for 45 to 55 minutes, stirring often, until the onions are deep brown and jammy.
- Add the sherry and scrape the pot for 2 minutes until nearly dry.
- Add the broth, Worcestershire and thyme and simmer for 20 minutes, then heat to 165°F.
- Toast the baguette slices until dry and set one over each oven-safe bowl of soup.
- Top with provolone and broil for 2 to 3 minutes until browned and bubbling.