3 Tbsp. Butter
3-4 Large Yellow Onions (3 Lbs.) thinly sliced
3/4 Tsp Salt
6 Cups Beef Stock
1 Cup Dry White Wine
1 Tbsp. Dry Sherry
3 Tbsp. Flour
1 Tbsp. Jugo (or Worcestershire Sauce)
2 Bay Leaves
1 Tsp. Thyme
! Tsp. Black Pepper
Baguette
Gruyere Cheese
Melt butter in heavy Dutch oven over medium heat. Add onions and 1/2 teaspoon salt, stir and cover, letting onions soften for 5 minutes. Remove lid and let onions caramelize until golden brown over medium heat, stirring occasionally. Adjust heat if onions are browning too quickly. This process can take up to 60 minutes.
Warm broth in a saucepan. Once onions are caramelized, add wine and sherry to the pot and allow mixture to come to a boil. Stir in flour and let thicken for a minute or two. Add the broth, Jugo, bay leaf, pepper and thyme and stir to combine. Continue to cook until the soup reaches a simmer. Reduce heat, cover and simmer for a least 10 minutes. Discard bay leaf and season with salt and pepper as needed.
Preheat the oven to 400°. Slice the baguette into 1inch slices and place in a single layer on a baking sheet. Bake for 6-8 minutes until the bread is toasted and golden. Remove and set aside.
Switch the oven to broil. Once the soup is ready to serve, ladle it into oven-safe bowls and place on a baking sheet. Then top with baguette slices and shred a desired amount of Gruyere on top. Place on oven rack about 6 inches from the broiler and broil for 2-4 minutes or until the cheese is melted, bubbly and browned.