EN DE FR ES PT IT
Light French Onion Soup
Recipe

Light French Onion Soup

Starter • France

Slow-cooked onions build natural sweetness and depth, finished with a small Gruyère-topped baguette slice for the classic French touch—without turning the soup heavy.

Why smarter

Uses moderate olive oil, a broth-forward base, and a restrained portion of bread and cheese while keeping flavour high through proper caramelisation and herbs.

Chef tip

Caramelise patiently: keep the heat medium-low and deglaze in small splashes—this lifts the fond and delivers big flavour without extra fat or sugar.

Soft line

Comforting, classic, and lighter—perfect as a simple French starter.

Ingredients

# Ingredient Text Amount Unit Ingredient Name Notes
1 4 large yellow onions, thinly sliced 4.000 large yellow onions Thin, even slices caramelise more evenly
2 2 tsp extra-virgin olive oil 2.000 tsp extra-virgin olive oil
3 1 tbsp unsalted butter (optional but traditional for flavour) 1.000 tbsp unsalted butter Can be replaced with 1 more tsp olive oil
4 2 cloves garlic, finely chopped 2.000 cloves garlic
5 1 tbsp plain flour 1.000 tbsp flour Lightly thickens and gives body
6 120 ml dry white wine 120.000 ml dry white wine Or replace with extra stock and 1 tsp cider vinegar
7 1.2 L low-sodium beef stock (or half beef, half vegetable stock) 1.200 L low-sodium stock
8 1 bay leaf 1.000 bay leaf
9 4 sprigs fresh thyme (or 1/2 tsp dried thyme) 4.000 sprigs thyme
10 1 tsp Dijon mustard (optional, for extra depth) 1.000 tsp Dijon mustard
11 Black pepper, to taste black pepper
12 Salt, to taste (go easy—stock can be salty) salt
13 4 thin slices baguette (about 120 g total) 4.000 slices baguette Thin slices keep it lighter
14 60 g Gruyère, coarsely grated 60.000 g Gruyère Comté also works well

Method

  1. In a large pot, warm the olive oil and butter over medium heat. Add the sliced onions with a pinch of salt and cook 10 minutes, stirring often, until softened.
  2. Reduce to medium-low and continue cooking 25–35 minutes, stirring regularly, until the onions are deep golden brown and jammy. If the pot starts to catch, splash in a tablespoon or two of water and scrape up the browned bits.
  3. Stir in the garlic and cook 30 seconds. Sprinkle over the flour and cook 1 minute, stirring to coat the onions.
  4. Pour in the white wine and simmer 2–3 minutes, scraping the bottom to deglaze fully.
  5. Add the stock, bay leaf, and thyme. Bring to a gentle simmer and cook 15–20 minutes. Stir in the Dijon mustard if using. Taste and adjust with black pepper and a little salt only if needed.
  6. Meanwhile, toast the baguette slices until crisp. Top each with a little grated Gruyère.
  7. Ladle soup into 4 bowls and float a cheese toast on each. If desired, briefly grill to melt the cheese before serving (or melt under a hot grill on a tray, then add to the soup).