Artisanal’s French onion soup

1. Preheat the oven to 325 degrees Fahrenheit. Bake the baguette slices until golden brown. Set aside. 2. Pour the canola oil into a large stockpot and warm over medium heat. Add the onions, shallots, and leek, and cook, stirring every few minutes, until they turn a dark amber brown, about 1 hour. Add the wine and sherry and scrape up any crusty bits while stirring. Cook until the wine is reduced by two-thirds, 8 to 10 minutes. 3. Add the stock and herb sachet. Bring to a boil over high heat, then lower heat and let simmer for 40 minutes, stirring occasionally. Discard the sachet, squeezing any liquid back into the pot, and season with salt and pepper. (Now the soup can be covered and stored in the refrigerator for up to 3 days. Bring the soup back to a boil before proceeding.) Stir the first 3 cheeses together in a bowl. Position a rack 4 inches below the broiler and preheat. Put four 8-ounce ovenproof crocks on a baking pan. Dividethe soup among them, filling so that the croutons will be flush with the top of the crock. Float 2 croutons on the soup in each bowl. Divide the cheese mixture among the crocks and sprinkle with Parmigiano-Reggiano. 4. Broil until the cheese is bubbly and golden, about 5 minutes. Serve immediately.