Name: Classic French Onion Soup with Gruyère and Baguette Toast Recipe
Prep time: 20 min
Cook time: 1 h 10 min
Total time: 1 h 30 min
Cuisine: French
Ingredients: 100 g / 3.5 oz unsalted butter; 1.25 kg / 2.5 lb brown or yellow onions, peeled, halved, thinly sliced top to bottom; 3/4 cup (185 ml) dry white wine (optional); 2 tbsp all-purpose flour; 1.5 litres / 6 cups / 1.5 quarts good quality beef broth or chicken broth, low sodium/salt reduced; 2 dried bay leaves or 3 fresh bay leaves (optional); 3 sprigs fresh thyme (optional); Salt and freshly ground black pepper, to taste; 6-8 slices French baguette or other softish bread; 100 g / 3.5 oz Gruyere cheese, or mozzarella or other melting cheese of choice; Fresh parsley or thyme leaves, for garnish (optional)

Ingredients

100 g / 3.5 oz unsalted butter

1.25 kg / 2.5 lb brown or yellow onions, peeled, halved, thinly sliced top to bottom

3/4 cup (185 ml) dry white wine (optional)

2 tbsp plain/all-purpose flour

1.5 litres / 6 cups / 1.5 quarts good quality beef or chicken broth/stock, low sodium

2 dried bay leaves or 3 fresh (optional)

3 sprigs fresh thyme (optional)

Salt and pepper, to taste

6 to 8 slices French baguette or other soft bread

100 g / 3.5 oz Gruyere cheese or mozzarella (or other melting cheese of choice)

Fresh parsley or thyme leaves for garnish (optional)

Instructions

Step 1: Melt the butter in a heavy-based casserole pot over medium heat. When it starts to foam, add the sliced onions and stir to coat them evenly with the butter.

Step 2: Reduce the heat to medium low. Cook the onions for about 30 minutes, stirring every few minutes until they soften and become semi-transparent.

Step 3: Increase the heat to medium or medium high, add a pinch of salt, and continue cooking the onions for another 20 to 30 minutes. Stir regularly until they turn a deep golden color and develop a sweet aroma.

Step 4: If using, add the white wine to deglaze the pot. Simmer rapidly for 2 minutes while scraping the bottom to lift any browned bits.

Step 5: Sprinkle the flour over the onions and cook for 1 minute to remove the raw taste.

Step 6: Pour in the broth and add the bay leaves and thyme sprigs. Stir to combine.

Step 7: Cover the pot and lower the heat to maintain a gentle simmer. Cook for 30 minutes to meld the flavors.

Step 8: Season the soup with salt and pepper to taste. Remove the bay leaves and thyme sprigs before serving.

Step 9: Preheat the grill or broiler to high. Toast slices of bread on both sides until lightly golden.

Step 10: Place the toasted bread slices on top of the soup in bowls. Cover with grated cheese, then grill until the cheese melts and develops golden brown spots.

Step 11: Garnish with fresh parsley or thyme if desired, and serve immediately.

Tips & Variations

Use low sodium broth to better control the saltiness of your soup.

For a vegetarian version, replace beef broth with rich vegetable stock.

Gruyere cheese offers the best melt and flavor, but mozzarella or Swiss cheese works well as alternatives.

If you prefer, caramelize the onions slowly in a slow cooker for 6–8 hours for deeper flavor.

FAQs

Can I make French Onion Soup without wine?

Yes, the wine is optional and mainly used for deglazing and adding depth of flavor. You can skip it or substitute with extra broth or a splash of apple cider vinegar for acidity.

What type of bread is best for French Onion Soup?

A soft but sturdy bread like French baguette works best. It soaks up the soup without becoming too soggy and provides a good base for the melted cheese topping.