Real French Onion Soup

Ingredients

• 3 tbsp Unsalted butter
• 1 tbsp Extra-virgin olive oil
• 6 Yellow onion, halved and sliced thin
• 1 ¼ tsp Kosher salt
• 1 tsp Granulated sugar
• 4 cloves Garlic, minced
• 2 tbsp All-purpose flour
• 1 cup Dry white wine
• 6 cups Low-sodium vegetable broth
• 1 tbsp Low-sodium soy sauce
• 6 sprigs Fresh thyme
• 2 Bay leaves
• 1 tbsp Balsamic vinegar
• ½ tsp Black pepper
• 12 slices Baguette
• 6 oz Gruyère, grated

Method

1. Melt the butter with the oil in a dutch oven over medium. Add all the onions with the salt and sugar. They will look like far too many. They will cook down to a quarter of that.
2. Cook 45-55 minutes, stirring every 5-8 minutes and scraping the brown film off the bottom each time. That film is the flavour. If the pan looks dry and dark, add a splash of water and scrape. Do not raise the heat to hurry it — you get burnt edges and raw centres.
3. When the onions are deep amber and jammy, add the garlic and cook 1 minute. Stir in the flour and cook 2 minutes to lose the raw taste.
4. Pour in the wine and scrape the bottom clean. Simmer until it is nearly gone, about 4 minutes.
5. Add the broth, soy sauce, thyme sprigs and bay leaves. The soy is not a flavour you will taste — it is doing the savoury work beef broth normally does. Simmer 20 minutes.
6. Fish out the thyme stems and bay. Stir in the balsamic and pepper, then taste. It should make you want another spoonful immediately; if it does not, it needs salt or another splash of vinegar.
7. Toast the baguette slices. Ladle soup into oven-safe bowls, float two slices on each, pile on the Gruyère, and broil 2-3 minutes until the cheese is bubbling and blistered in spots. Let them sit 2 minutes — molten cheese is a real burn risk.

Notes

✨ The restaurant touch

Grate the Gruyère yourself and let a little fall down the outside of the bowl. It bakes onto the rim and you get a crisp cheese edge, which is the best bite in the whole dish.

🧒 For the kids

Serve theirs in a regular bowl with the cheese toast on the side, unbroiled. The bowl-under-a-broiler part is the fun of it, but it comes out at 400°F.

🌿 From the garden

Onions and thyme both come out of a small bed easily. Six storage onions from an August harvest is a single row — and this soup is what storage onions are for in February.

🥡 Leftovers

The soup base keeps 5 days refrigerated and 3 months frozen, and genuinely improves overnight. Toast and broil fresh bread each time; a soggy raft reheated is a sad thing.

Per serving

Computed from USDA FoodData Central values. A planning tool, not medical advice.