French · Free
French Onion Soup
Deeply caramelized onions simmered in rich beef broth, topped with toasted bread and a blanket of melted Gruyere. Patience with the onions rewards you with a soup of extraordinary sweet, savory depth.
****+
Prep 20 min · Cook 75 min
Method
Melt the butter with the olive oil in a large heavy pot over medium heat, then add all the sliced onions and the sugar; the onions will look like far too much, but they will shrink dramatically as they cook.
Cook the onions slowly, stirring every few minutes, for 40 to 50 minutes until they collapse into a jammy deep golden-brown mass; this caramelization is the heart of the soup, so resist rushing it with high heat, which would burn rather than sweeten them.
If the onions start sticking or browning too fast, lower the heat and add a splash of water to loosen the browned bits from the bottom of the pot.
Once the onions are richly caramelized, stir in the garlic and cook for 1 minute, then sprinkle in the flour and stir for 2 minutes to cook out the raw taste and lightly thicken the soup.
Pour in the white wine to deglaze, scraping up all the flavorful browned bits from the bottom of the pot, and let it simmer for 2 minutes until slightly reduced.
Add the beef stock, thyme sprigs, and bay leaf, then bring to a simmer and cook uncovered for 20 minutes to let the flavors meld and deepen.
Remove the thyme sprigs and bay leaf, then taste and season with salt and pepper; beef stock varies in saltiness, so adjust carefully.
While the soup simmers, arrange the baguette slices on a baking sheet and toast under the broiler for 1 to 2 minutes per side until dry and golden; watch closely because they burn quickly.
Set your oven to broil and place four oven-safe bowls on a sturdy baking sheet, then ladle the hot soup into each bowl leaving about an inch of space at the top.
Float one or two toasted baguette slices on each bowl of soup, then pile the grated Gruyere generously over the bread and rims so it melts into a bubbling crust.
Broil the bowls 6 inches from the heat for 3 to 5 minutes until the cheese is melted, bubbling, and browned in spots; keep the oven door cracked and watch the whole time.
Carefully remove the very hot bowls using thick oven mitts, warn your guests, and let cool for a couple of minutes before serving.
Chef's tips
- The single most common mistake is undercooking the onions; they should be the color of dark honey, not merely soft and translucent.
- If you do not have oven-safe bowls, broil the cheese-topped toasts separately on a sheet pan and float them on the soup just before serving.
- A splash of brandy stirred in at the end adds a wonderful warm depth.
Cooking times vary by equipment -- cook to temperature and to taste.
