2cups(8 ounces) freshly-grated Gruyère of Comté cheese
1/2baguette, sliced 1/2" thick, maybe a little less
For the Soup
Peel, cut in half through the root end, and thinly slice the onions.
Heat the butter in a wide-bottomed pot over medium-low heat. Add the onions, thyme, bay leaves, and 1 teaspoon of salt. Cover the pot and reduce the heat to low. Cook, stirring often, until the onions have turned extremely soft and a deep golden brown, about 45 to 50 minutes. Tip: Stir often. You want the onions to caramelize, not brown or burn. Adjust the heat as necessary.
Remove the lid shortly before the onions have finished cooking, to evaporate the liquid. The bottom and low sides of the pot should form a deep brown crust.
Raise the heat to medium. Deglaze the pot with the white wine, scraping the brown bits and stirring. Let the liquid fully evaporate so that the pot forms another brown crust. Deglaze the pot with 1 cup of water, stirring and scraping as above until the liquid evaporates. Repeat with 1 more cup of water.PRO TIP: Why not just dump three cups of liquid all at once and let it evaporate? Because this way, you are building three times the rich brown caramelization that forms on the pot.
At this point, the onions should look chestnut brown and soft to the point of being the world's most delicious sludge pile. Add the quart of chicken stock and 1 cup of water. Bring to a boil, then lower the heat and let simmer, partially covered, for about 30 minutes. Stir occasionally.
While the soup simmers, place four French onion soup crocks on a rimmed baking sheet. Grate the cheese and toast two baguette slices per crock. Set aside.
Taste the soup for seasoning. It should be fairly thick. Adjust with a large pinch of sugar if necessary, and an additional teaspoon of salt or so.
Preheat the broiler and position the rack about 7" from the top of the oven. Spoon the soup into the crocks, leaving a little space from the rim. Lay a slice or two of baguette over the soup, and generously top with cheese.
Place the soup under the broiler until melted and bubbly and lightly browned on top, about 3 or 4 minutes. (Keep an eye on it!) Let rest for 2 minutes before serving. The top of the crocks are extremely hot, so take care.
Deeply caramelized onions swimming in rich broth, topped with bread and cheese make this homemade, classic French onion soup recipe better than any restaurant version. Take your time caramelizing the onions. Low and slow is the way to go for that sweet, silky result.