Delia Smith French Onion Soup

There’s something oddly emotional about French onion soup. It’s not flashy. Not trendy. And yet, it’s the one I go back to every winter — like rewatching an old film you know the ending to, but still love anyway.

The first time I made it properly — like caramelising onions from scratch rather than opening a sad tin — I was living alone in a flat with a dodgy hob and a chipped wooden spoon. I remember thinking, “Is this really worth 40 minutes of stirring onions?” And then… the smell happened. Deep, nutty sweetness, like roasted garlic had a lovechild with butter and magic. I stood barefoot on cold tiles, sipping cheap wine, and just let it all bubble. By the time it hit the bowl — golden toast dripping with melted Gruyère floating on top — I knew. It was a keeper.

This recipe is my slightly rambling, slightly reverent tribute to Delia’s version — with a few tweaks from too many solo dinners and one small fire (don’t leave the grill unattended).

Why You’ll Love It

• It smells like a French bistro. Even if your kitchen looks like a utility room.
• The onions go sweet, rich, and golden, like edible alchemy.
• You get to eat cheese on toast floating in soup. What’s not to love?
• It tastes way fancier than it is. No culinary degree required.
• You can make it ahead. And it’s even better the next day.
• It warms your bones. (And maybe your heart. Maybe.)

Ingredients

• 6 large red or yellow onions (about 3 lbs), sliced thin
• 4 tbsp extra virgin olive oil
• 2 tbsp butter
• 1 tsp sugar
• Kosher salt
• 2 garlic cloves, minced
• 8 cups beef stock, chicken stock, or a mix
• ½ cup dry vermouth or white wine
• 2 bay leaves
• 1 tbsp fresh thyme leaves (or ½ tsp dried thyme)
• ½ tsp freshly ground black pepper
• 2 tbsp brandy (optional, but lovely)
• 8 thick slices of French bread or baguette
• 1½ cups grated Gruyère cheese
• A handful of Parmesan, grated

How to Make It

Get weepy with the onions:

Slice your onions from root to tip — not across, trust me. It makes them melt better. Heat 3 tbsp oil in a big heavy-bottomed pot and dump in the onions with a pinch of salt. Stir. Let them sweat over medium-low heat for 15–20 mins. No rush.

Let them turn golden (but don’t wander off):

Crank the heat to medium-high. Add the last bit of oil and the butter. Stir every few minutes — you want deep brown, not burnt. This can take 20–40 minutes depending on your pot and patience. When they’re jammy and smell ridiculous, you’re there.

Add the garlic and sugar:

Toss in your garlic and sugar and give it another 10–15 mins. The sugar helps them caramelise further. This step smells so good, your neighbours might ask what you’re making.

Deglaze with wine (and joy):

Pour in the wine or vermouth. Use a wooden spoon to scrape up all the brown sticky bits from the bottom. That’s the gold. Breathe in. Smile.

Simmer the goodness:

Add your stock, bay leaves, thyme, pepper. Bring it to a gentle simmer, cover, and let it do its thing for 30 minutes. Taste and adjust seasoning. Add brandy if you fancy it. I always do.

Make cheesy toast boats:

Brush both sides of your bread slices with olive oil and toast them in a 450°F oven for 5–7 mins. Sprinkle with Gruyère and Parmesan, then grill until bubbly and golden. Try not to eat one before serving. (I fail every time.)

Assemble your masterpiece:

Ladle the soup into bowls and gently float your cheesy toast on top. Or, if you’ve got oven-safe bowls, chuck the lot under the grill until the cheese melts into a golden crust. Fancy.

Common Mistakes and How to Dodge Them

Why are my onions bitter?
Heat too high. Stir too little. Burnt bits sneak in. Low and slow is your friend here.

Soup tastes flat?
Salt. Wine. Brandy. Don’t be shy — seasoning is everything.

Cheesy toast turned soggy?
You probably didn’t toast the bread enough first. Give it a proper crunch before the cheese.

Can I skip the wine?
Yep — just add a dash of vinegar or lemon juice to balance the sweetness.

My onions aren’t browning.
Keep going. Or try a wider pan. It’s a patience game, not a speed race.

Storage and Reheating

• Fridge: Keeps in a sealed container for 3–4 days.
• Freezer: Freeze without toast for up to 3 months. Defrost gently.
• Microwave: Fine, but toast separately.
• Stovetop: Best method — low heat, stir often.
• Oven (for toast): Re-toast bread with cheese at 200°C until bubbling.

Frequently Asked Questions

Can I use pre-sliced onions?
You can. But they won’t melt the same way. Real ones are worth it.

Is it OK to use veggie stock?
Absolutely — just use a rich one. Add soy sauce or miso if you want that umami depth.

Can I make this ahead for a dinner party?
Yes. Make the soup a day ahead and reheat. Toast just before serving.

What if I don’t have Gruyère?
Try Emmental, Jarlsberg, or even a punchy mature cheddar. It’ll still be lush.

Nutrition Facts (Per Serving)

• Calories: 699
• Fat: 26g
• Carbs: 84g
• Sugar: 14g
• Protein: 30g
• Sodium: 1727mg

More Delia Smith Recipe:

• Delia Smith Beetroot Soup
• Delia Smith Cauliflower Soup
• Delia Smith Celery Soup