1. Melt the butter in a large stockpot or Dutch oven over medium-high heat. Add the slice onions and 1/2 teaspoon salt, stir to coat the onions thoroughly with butter. 2. Cook, stirring frequently, until the onions are reduced and syrupy and the inside of the pot is coated with a very deep brown crust, 30 to 35 minutes. Adjust heat to ensure that onions and crust is browning, not burning. 3. Stir in the chicken and beef broths, red wine, parsley, thyme and bay leaf, scraping the pot bottom with a wooden spoon to loosen the browned bits and bring to a simmer. Simmer for 20 minutes, to blend the flavors. 4. Remove and discard the herbs (parsley, thyme and bay leaf). Stir in the balsamic vinegar and 5. Adjust an oven rack to the upper-middle position. Heat the broiler and optionally toast baguette slices. Remove and set aside. 6. Set oven-safe crocks or bowls on a baking sheet. 7. Fill each dish with soup, about 1 1/2 cups. Top each bowl with 2 baguette slices and cover with a single layer of the provolone or Swiss cheese. Sprinkle with about 2 Tbsp of the asiago. 8. Broil until well browned and bubbly, about 10 minutes. 9. Cool for 5 minutes and serve. ---------------------------------------------------------------------------
Nutrition
Ingredients
