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The starter, French classic

French onion soup gratinée

French onion soup gratinée is a classic winter starter for 6 people, needing 35 minutes of active work out of 2 hours total. The soup base is made entirely the day before, leaving only the cheese to melt under the broiler before serving. It's an easy recipe at €1.60 per person, and its success depends on cooking the onions low and slow until they turn caramel colored.

I suggest French onion soup, with its stretchy gruyère and piping hot bowls, the kind of starter that makes everyone fall back in love with winter.

French onion soup gratinée
For
6 people
Work
35 min
Total time
2 h
Prep
Prepared the day before
Difficulty
Easy
Cost per person
€1.60
Calories per person
380 kcalcalculated by Kiloach, your weight coach

Under the melted gruyère crust, onions cooked down for nearly an hour turn into a soup that's brown, sweet and deep, far from the pale, thin broth some people picture. The toasted bread floating in the middle soaks up the broth without falling apart, and the cheese stretching as you break the crust always gets a reaction at the table.

This is a starter that warms up a winter dinner with friends or a family meal, without demanding any last minute attention since everything is made the day before. It opens the way nicely for a simpler main afterward, like a braise or roast chicken, since guests arrive already satisfied by these generous bowls.

The schedule

What happens when, so you can be with your guests instead of in the kitchen.

  1. The day before 3 steps, 1 h 15
  2. The same day Nothing to do
  3. Before the guests arrive 1 step, 20 min
  4. When it's time to serve 1 step, 8 min

The day before, cook the onions down until caramelized, add the liquid and let the soup simmer, then let it cool and refrigerate it once you've removed the thyme. Just before guests arrive, toast the bread slices and reheat the soup in individual bowls. At serving time, top with gruyère and broil for a few minutes before bringing the hot bowls straight to the table.

The ingredients

6 people

Fruits and vegetables

  • Yellow onions 1.2 kg
  • Thyme 4 sprigs

Dairy

  • Butter 50 g
  • Grated gruyère 200 g

Pantry

  • Flouroften in the pantry 2 tbsp
  • Dry white wine 20 cl
  • Vegetable broth 150 cl
  • Saltoften in the pantry 1 pinch
  • Pepperoften in the pantry 1 pinch

Bakery

  • Baguette 1

Allergens Gluten, Lactose, Celery

The recipe, moment by moment

The day beforeWhat's better after resting overnight in the fridge.

  1. Thinly slice the onions and cook them down in the butter over low heat, stirring often. 45 min

    Add a pinch of sugar after ten minutes, it speeds up caramelization without changing the flavor.

  2. Sprinkle with flour, pour in the white wine then the broth, add the thyme, season with salt and pepper, and let it simmer. 30 min

    Pour in the hot broth in three additions, the soup stays smooth with no lumps.

  3. Let the soup cool, remove the thyme, and refrigerate it.

    A night in the fridge and the onions taste even better.

Before the guests arriveThe last hour, right before the doorbell rings.

  1. Slice the baguette, toast the slices in the oven, then reheat the soup and divide it among six oven safe bowls. 20 min

    Dry the croutons well, if they're soft they sink to the bottom and the gratin won't hold.

When it's time to serveThe final touches, right in front of your guests.

  1. Top the soup with the croutons, cover with gruyère, and broil until the cheese turns golden and bubbly. 8 min

    Set the bowls on a baking sheet, you'll be able to pull them out without burning yourself or spilling a drop.

Our tips to get it right

  • Use a wide pot rather than a tall one, onions caramelize better spread in a thin layer than piled up.
  • Pick a dry white wine you'd actually drink, its acidity balances the sweetness of the cooked down onions.
  • Choose ceramic or oven safe glass bowls, tall enough that the cheese can bubble and brown without spilling over.

The variations

  • Swap the gruyère for comté or emmental if you want a milder, less assertive flavor.
  • For a gluten free version, use gluten free flour to thicken and toast gluten free bread for the croutons.
  • To save time on the day, make the base ahead exactly as described, then just reheat and broil, since the longest step is already done.

What to serve it with

  • A simple green salad after
  • A dry white Burgundy wine
  • A braised main dish next

Storage

The soup without the cheese topping keeps 2 to 3 days in the refrigerator in a sealed container. It freezes well without the croutons or cheese, for up to 2 months. Reheat it gently over low heat before adding the croutons, gruyère, and finishing under the broiler.

Questions about this recipe

Can you use red onions instead of yellow onions?

Red onions work but give a sweeter soup and a darker color. Yellow onions stay the classic choice for this recipe, with a more balanced flavor.

How do you keep the croutons from going soggy too fast?

Toast them until golden and crisp before placing them on the hot soup. Well dried croutons hold up better and won't sink to the bottom of the bowl.

Can you replace the white wine with something else?

You can use extra broth with a splash of cider vinegar to keep some acidity. The flavor will be a touch less complex but the soup still works well.

What kind of bowls should you serve this soup in?

Pick individual oven safe bowls, either ceramic or heat resistant glass. They need to be tall enough to hold the soup, the crouton, and a good layer of gruyère without overflowing under the broiler.

Can a French onion soup gratinée be made ahead?

Yes, it's even recommended. The recipe needs 35 min of work in total, split up like this, the day before, 3 steps, before the guests arrive, 1 step, when it's time to serve, 1 step.

How long does it take to make a French onion soup gratinée?

Allow 2 h in total, including resting and cooking time, of which 35 min is actual work. The recipe is rated "easy".

How many calories are in a French onion soup gratinée?

About 380 kcal per person, for a recipe meant for 6 people. The calories are calculated by Kiloach, your kilo coach, the app that partners with Mon Chou.

How much does a French onion soup gratinée cost?

About €1.60 per person, that's €9.60 for 6 people, based on average supermarket prices.

What allergens does this recipe contain?

This recipe contains gluten, lactose, celery. Remember to ask your guests about their allergies before putting your menu together.

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