French Onion Soup

From the kitchen of Carly

The bistro classic: deeply caramelized onions, beef stock, white wine, and a raft of toasted bread under blistered Gruyere. The whole thing rises and falls on how patient you are with the onions, so settle in. Yes, 30 minutes on the onions. Set a timer, get a podcast. Stir every few minutes. Don't crank the heat to speed it up.

French Onion Soup

Onion soup lives or dies on patience. A kilogram of onions that look impossible at first collapses into pure caramelized gold, jammy and deep enough to anchor an entire bowl with nothing but beef stock and bread. The cheese crust matters, but it's the onions that make you come back for another spoonful.

Prep
10 min
Cook
1 hr 10 min
Total
1 hr 20 min
Servings
4
Difficulty
easy

Ingredients

4 servings

  • 2 oz(50 g)unsalted butter
  • 1 tbspolive oil
  • 1 kg (about 5 large)yellow onions, thinly sliced
  • 1 tspgranulated sugar
  • 4garlic cloves, sliced
  • 2 tbspall-purpose flour
  • 1 cup(250 ml)dry white wine
  • 4 1/4 cups(1 L)beef stock, hot
  • 4thick slices of country bread, toasted
  • 5 oz(140 g)Gruyere, grated

Instructions

  1. Melt the butter and oil in a large heavy pot over medium-low heat.

  2. Add the sliced onions. Cover and cook 10 minutes, stirring once or twice, just to soften.

  3. Uncover. Sprinkle in the sugar. Cook 25 to 30 minutes more, stirring every few minutes, until the onions are deeply golden and jammy. They should reduce to about a quarter of their original volume. Don't rush this; pale onions equal pale soup.

  4. Add the sliced garlic in the last 2 minutes of caramelizing.

  5. Sprinkle the flour over the top and stir well. Cook 1 minute more.

  6. Increase the heat to medium-high. Pour in the white wine, stirring constantly. Let it bubble hard for 2 minutes to cook off the alcohol.

  7. Pour in the hot beef stock. Stir, then cover and simmer 20 minutes.

  8. Taste. Season with salt and pepper. The deep onion flavor should carry the soup; salt to enhance, not dominate.

  9. Heat the broiler.

  10. Ladle the soup into 4 oven-safe bowls. Float a slice of toasted bread on each. Pile the grated Gruyere over the top, covering the bread completely.

  11. Place the bowls on a baking sheet. Slide under the broiler 2 to 3 minutes, until the cheese is bubbling and blistered at the edges.

  12. Serve immediately, warning everyone the bowls are very hot.

Make ahead and storage

Refrigerate the soup without the cheese and bread for up to 4 days. Reheat gently on the stovetop, then assemble with fresh toast and cheese under the broiler right before serving. The soup freezes well for up to 3 months; skip the bread and cheese entirely until you're ready to eat it.

Tips from the kitchen

  • Don't skip the covered phase at the start. Those first 10 minutes steam the onions into submission so they actually cook down evenly without burning on the bottom. Your arms will thank you.
  • Caramelizing 1 kg of onions takes real time, not a shortcut. Keep stirring every few minutes. When they go from translucent to golden to deep mahogany, that's when they taste like something.
  • Toast your bread slices ahead of time so they don't get soggy before the cheese hits. A hard, dry surface under hot cheese is what you want here.

Variations

  • Skip the white wine if you don't have it: use an extra splash of beef stock instead and add 1 tbsp sherry vinegar at the end for brightness.
  • Swap Gruyere for aged Emmental or sharp cheddar if that's what you've got. Anything nutty and melty works.
  • Make it meatier by stirring in a spoonful of beef marrow or pancetta bits just before you ladle it into bowls.
  • Go vegetarian by using vegetable stock and a splash of balsamic vinegar in place of the wine to deepen the flavor.
Substitutions
  • Gruyere to Comte, Emmental, or sharp Swiss. Comte is the upscale move; Emmental is what most groceries stock. Skip pre-shredded; it doesn't melt cleanly.
  • beef stock to homemade or low-sodium chicken stock + 1 tbsp soy sauce. Soy sauce adds the umami depth beef stock provides. Better than thin store-bought beef broth.
  • dry white wine to dry sherry or extra stock + 1 tsp red wine vinegar. Sherry is classic in some French versions. The vinegar mimics the acid the wine would have provided.

Pairs well with: A simple green salad with mustard vinaigrette, A glass of Burgundy or any pinot noir, Buttered baguette on the side for sopping