French Onion Soup with Cheese Crouton Recipe
French onion soup is a simple dish that workers once ate after the night shift to warm up. Slowly stewed onions turn into something sweet and deeply flavorful, and the baked cheese-topped crouton on top turns this soup into a full meal. It’s a great choice for a chilly evening when you want to really warm yourself up.
Slowly caramelized onions give this soup a deep, sweet and savory flavor, while the baked cheese crouton on top turns a simple bowl of soup into a comforting, filling meal.
Chef's tips
Take your time with the onions—don’t rush the caramelization stage. Keeping the heat low and stirring regularly is key to developing flavor without burning. If you don’t have ovenproof bowls, you can toast the bread with cheese separately and float it on the soup just before serving.
How to serve
Serve very hot in deep bowls, with extra grated cheese on the side for topping. A simple green salad with a mustard vinaigrette makes a nice contrast, and crusty bread is always welcome for mopping up the last drops.
Ingredients
- onion regular yellow - 800 g
- butter - 40 g
- vegetable oil - 1 tablespoon
- stock vegetable or chicken - 1 l
- white wine optional, dry - 100 ml
- baguette or other light bread - 8 slice
- yellow cheese hard, melts well, grated - 120 g
- thyme dried leaves or a few sprigs fresh - 0.5 teaspoon
- bay leaf - 2 piece
- salt to taste
- black pepper to taste
- sugar optional, to boost the onion’s sweetness - 0.5 teaspoon
Preparation
- Peel the onions, cut them in half and slice into thin half-moons.
- In a large pot, heat the butter with the oil over medium heat. Add the onions and a pinch of salt. Fry for 10 minutes, stirring often, until they soften.
- Reduce the heat to low and cook the onions for 25–30 minutes, stirring every few minutes, until very soft, golden brown and lightly caramelized. If they start to burn, lower the heat and add 1–2 tablespoons of water.
- Add the sugar (if using) and cook for another 2–3 minutes, stirring, until the onions smell very sweet.
- Pour in the wine, if using, and cook for 3–4 minutes until most of the liquid evaporates. Then pour in the stock and add the bay leaves and thyme.
- Bring the soup to a boil, then reduce the heat and simmer gently for 15–20 minutes. Season with salt and pepper to taste, remove the bay leaves.
- Meanwhile, preheat the oven to 200°C. Place the baguette slices on a baking tray and bake for 5–7 minutes, until dry and lightly crisp.
- Ladle the hot soup into ovenproof bowls. Place 1–2 slices of baguette on top of each portion and generously sprinkle with grated cheese.
- Set the bowls on a baking tray and bake for 8–10 minutes, until the cheese melts and is lightly browned. Serve very hot, taking care with the temperature of the cheese.
Storage
Zupę bez grzanek przechowuj w lodówce w zamkniętym pojemniku. Podgrzewaj na małym ogniu, w razie potrzeby dolej trochę wody. Możesz zamrozić samą zupę do 2 miesięcy, grzanki i ser dodawaj zawsze świeże.
This is one of those recipes where patience really pays off. The longer, slower you cook the onions, the more complex the flavor becomes—and that’s what makes this humble soup feel like a restaurant classic.
