Jamie Oliver French Onion Soup

There’s something almost theatrical about making French onion soup. The slow sizzle of butter, the tear-inducing onions, the moment the vermouth hits the pan and your kitchen smells like a Parisian bistro in full swing. It’s a dish that asks for patience — and pays you back with deep, golden sweetness and that glorious, gooey cheese moment on top.

I first made this soup on a chilly Sunday afternoon when I was broke and craving comfort. I had onions, some old sourdough, and half a wedge of Gruyère someone had left behind at a dinner party. I made it in my dressing gown with the windows open, letting the neighbours get a whiff (you’re welcome). And let me tell you — this soup is a love letter in a bowl. It’s warm, rich, and feels way fancier than it really is.

And the cheesy croutons? Let’s be honest — they steal the show. Toasted on one side, mustard-smeared on the other, dunked and grilled until bubbling. Pure heaven.

Why You’ll Love It

• That slow-cooked onion sweetness — nothing else like it.
• Cheesy mustard croutons make it feel indulgent and posh.
• Perfect for chilly nights or when you just need a hug in a bowl.
• Freezes like a dream — great for batch cooking.
• One pot, low effort (just give it time).
• Smells absolutely unreal while it simmers.

Ingredients

• 4 large onions (about 1kg)
• 25g unsalted butter
• Olive oil (1 tbsp to start)
• 2 cloves garlic
• 1 tbsp dark brown sugar
• 50ml dry vermouth or brandy
• 1.5 litres organic beef stock
• A few dashes of Worcestershire sauce
• 8 small slices sourdough baguette (or a small rustic loaf)
• 2 tbsp Dijon mustard
• 100g Gruyère cheese

How to Make It

Soften those onions:

Peel and finely slice the onions (a food processor helps if you’re prone to weeping). Cook them low and slow in a large pan with butter, olive oil, and a bit of salt and pepper. Lid on, about 10 minutes, until they’re soft but not yet coloured.

Let them caramelise:

Grate in the garlic and stir through the brown sugar. Cook for another 15 minutes, lid off, stirring now and then, until the onions are golden and jammy. Don’t rush this bit — it’s where the magic happens.

Add a bit of drama:

Pour in the vermouth or brandy. Let it simmer for a second, then (optional but thrilling) carefully tilt the pan to flambé — or light it with a match and stand back! Once the flame dies down, stir and take in that smell. Heaven.

Simmer it slow:

Add the beef stock, cover, and let it bubble gently for about 20 minutes. Taste, then season with salt, pepper, and a few shakes of Worcestershire. It should be deep, savoury, slightly sweet.

Prep the croutons:

Slice your bread and toast one side under the grill. Flip, spread the untoasted side with Dijon mustard, and set aside while your soup finishes.

Grill the whole thing:

Once the soup’s ready, float the croutons mustard-side-down on top of the soup in the pan. Pile on the grated Gruyère and grill the whole thing for 2–3 minutes until bubbling and golden.

Serve and swoon:

Ladle into bowls and top each with a couple of those gooey, cheesy croutons. Eat hot. Ideally with a glass of red and a big blanket.

Common Mistakes and How to Dodge Them

Why does it taste bitter?
You may have cooked the onions too hot or burned the garlic. Keep the heat low and slow — this soup rewards patience.

Too thin?
Let it simmer uncovered a little longer to reduce and concentrate the flavour.

Can’t flambé?
No worries. Just simmer the vermouth or brandy for a few minutes to cook off the alcohol.

Don’t have Gruyère?
Use Emmental, Comté, or even a sharp cheddar in a pinch. Just make sure it melts nicely.

Storage and Reheating

Fridge: Keeps well for 3–4 days in a sealed container. Flavours deepen overnight.
Freezer: Absolutely. Freeze in batches without the croutons.
Reheating: Gently warm on the stove. Toast fresh bread with cheese and mustard just before serving.

Frequently Asked Questions

Can I make it vegetarian?
Yes — use rich vegetable stock and skip the Worcestershire sauce (or find a veggie-friendly version).

Can I make it ahead?
Totally. The soup actually improves with time. Just grill the croutons fresh when you’re ready to eat.

What if I don’t drink alcohol?
You can skip the vermouth/brandy and add a splash of apple juice or just a bit more stock for depth.

Can I make this in a slow cooker?
Sure, cook the onions on the stovetop first, then transfer to the slow cooker with the rest of the ingredients (minus the croutons) and let it go on low for 4–6 hours.

Nutrition Facts (Per Serving):

• Calories: ~280
• Fat: 15g
• Carbs: 28g
• Protein: 9g
• Sodium: ~560mg
• Sugar: ~8g