2cups leeks (about 3 leeks), white and light green part only, washed thoroughly and sliced thin
3-4shallots, sliced thin
1clove garlic, minced
salt and pepper
1/2cup dry sherry
3/4cup dry white wine (like Sauvignon Blanc)
4 1/2cups chicken stock
4-6baguette slices, toasted in oven until crisp and golden brown
1pound Gruyere cheese, grated
thyme leaves, for garnish
In a large pot over medium high heat, melt the butter. Once heated, add all of the onions and garlic. Stir to coat them in the butter and cook until softened, about 10 minutes. Once the onions start to break down, lower the heat to medium low and cook, stirring frequently and scraping up any brown bits on the bottom as to not burn, until the onions are golden brown, anywhere from 45 minutes to an hour (or longer, depending). Season liberally with salt and pepper.
Deglaze the pan with the sherry and bring to a simmer and cook for 2-3 minutes. Add the wine and cook 2-3 minutes longer until the alcohol has had a chance to cook off. Add the bay leaf and sprigs of thyme, followed by the stock and raise the heat and bring the soup to a simmer. Lower the heat and cook for 15 minutes, uncovered.
To serve, pre heat the broiler to high. Discard the bay leaf and thyme sprig, and ladle the soup into 4 oven-proof crocks. Top with the toasts (use 1-2 depending upon how much soup the slices cover, but don’t overlap) and then sprinkle the cheese on top. Broil until the cheese is melted and starting to turn golden brown. Remove from the oven and garnish with thyme. Serve immediately.