Light French onion soup

French onion soup in a lighter but still comforting version: melting, caramelised onions in a fragrant broth, topped with a little melted cheese. Inexpensive and low in calories, it is the ultimate cosy dinner for winter evenings, perfect for warming up without overdoing it.

Preparation: 15 min  |  Cooking: 40 min  |  Servings: 4  |  Difficulty: Easy

Calculated per serving from Anses Ciqual 2025 values for each ingredient, based on the quantities in the list. Household measures (spoonfuls, pieces) use average weights. 198 kcal · 6 g protein · 24 g carbohydrate · 8 g fat

Ingredients

• 6 onions
• 1 litre stock
• 4 slices of wholemeal bread
• 60 g grated cheese
• 1 tbsp olive oil
• thyme, salt, pepper

Method

1. Slice the onions thinly and caramelise them gently for 20 minutes in the oil, until golden.
2. Pour in the stock, add the thyme and simmer for 15 minutes.
3. Divide the soup between ovenproof bowls and top each with a slice of wholemeal bread and the cheese.
4. Pop under the grill for a few minutes until bubbling and golden.

Nutritional benefits

Onion soup is naturally low in calories: slowly caramelised onion develops a rich flavour without added fat, while providing fibre and antioxidant sulphur compounds. By using wholemeal bread and a reasonable amount of cheese for the topping, you keep the pleasure of the classic while limiting the calories. It is a comforting, inexpensive dinner, ideal for weight loss on cold evenings.

Variations and substitutions

• Dairy-free: no cheese, or a plant-based alternative.
• Gluten-free: gluten-free bread croutons or no bread.
• Higher in protein: a poached egg in the soup.
• With herbs: bay leaf, white wine (the traditional way).

Storage and making ahead

The soup base (without the bread and cheese topping) keeps for 3 to 4 days in the fridge and can be frozen. Grill the topping at the last moment to keep the bread crisp and the cheese stringy.

💡 Good to know

It is all about caramelising the onions: take the time to brown them slowly over a low heat without burning them. This step gives the soup its deep, sweet flavour.

See also

Discover more weight-loss recipes · vegetarian recipes · healthy & balanced recipes.

Ingredients in this recipe: onions · stock · wholemeal bread · cheese · olive oil.

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