French

French Onion Soup

Soupe a l'oignon gratinee. Almost nothing in it but onions, and the entire dish depends on caramelising them far longer than feels reasonable.

Time
1 hr 30 mins
Serves
4
Steps
7
Ingredients
10
French onion soup topped with toasted baguette and melted gruyere

Method

  1. 01

    Melt the butter in a heavy pot and add the onions with a good pinch of salt.

  2. 02

    Cook over medium-low heat for 50 minutes, stirring every few minutes. They should collapse to a deep jammy brown - at 20 minutes they are only soft, which is not the same thing.

  3. 03

    Scrape the dark crust off the bottom of the pot as it builds; that is pure flavour.

  4. 04

    Stir in the flour and cook 2 minutes.

  5. 05

    Pour in the extra cup of stock with the lemon juice, scraping the base clean, and reduce by half.

  6. 06

    Add the stock, thyme and bay, then simmer 30 minutes and season.

  7. 07

    Ladle into ovenproof bowls, float toasted baguette on top, bury it in gruyere and grill until bubbling and blistered.

Cooking Tips

  • Give the onions the full 50 minutes. At 20 minutes they are merely soft, which is not the same as caramelised.
  • Scrape the dark crust off the bottom of the pot as it builds - that is pure flavour going back into the soup.

Ingredient Substitutions

  • Extra stock plus lemon juice replaces the usual splash of wine and keeps this alcohol-free.
  • Comte or a mature cheddar can stand in for gruyere.

What to Serve With It

  • Serve in ovenproof bowls, grilled until the cheese blisters.

Storage and Reheating

  • The soup base keeps 4 days and freezes for 3 months. Add bread and cheese only at serving.