Gruyère French Onion Soup
A deeply savory French soup with slowly caramelized onions, thyme and vegetable broth, finished with toasted baguette and a bubbling layer of Gruyère and Parmesan-style cheese.
Equipment
- Baking sheet
- Dutch oven or large pot
- Knife
- Oven-safe soup bowls
- Soup ladle
- Wooden spoon
Ingredients
- For the Onion Soup
- 4 large yellow onions thinly sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- 4 cups vegetable broth
- 1 teaspoon dried thyme
- 1 bay leaf
- 1/2 teaspoon fine salt or to taste
- 1/4 teaspoon ground black pepper or to taste
- For the Cheese Toasts
- 4 slices baguette or crusty bread
- 200 g vegetarian Gruyère-style cheese shredded
- 100 g vegetarian Parmesan-style cheese finely grated
Instructions
- Melt the butter with the olive oil in a Dutch oven over medium heat.
- Add the sliced onions.
- Reduce the heat to medium-low.
- Cook for 35 to 40 minutes.
- Stir every few minutes until the onions become soft, deeply golden and caramelized.
- Add a splash of water if the onions begin sticking before they caramelize.
- Pour in the vegetable broth.
- Add the thyme and bay leaf.
- Bring the soup to a gentle simmer.
- Cook uncovered for 10 minutes.
- Remove the bay leaf.
- Season with salt and black pepper.
- For the Cheese Toasts
- Preheat the oven to 200°C.
- Arrange the baguette slices on a baking sheet.
- Toast for 5 to 7 minutes.
- Turn the bread halfway through the cooking time.
- Preheat the broiler.
- Divide the hot soup among 4 oven-safe bowls.
- Place one toasted baguette slice on each bowl.
- Combine the Gruyère-style and Parmesan-style cheeses.
- Divide the cheese evenly over the bread.
- Place the bowls under the broiler.
- Broil for 2 to 3 minutes until the cheese has melted and developed golden spots.
- Remove the bowls carefully.
- Serve immediately.
Notes & Wine Advice
Serving Suggestions
Serve the soup immediately with a simple green salad. The cheese-topped baguette makes each bowl quite filling, so additional bread is optional.Recipe Notes
Slow caramelization gives the soup its characteristic depth. Keep the heat at medium-low and allow the onions to become deeply golden. Increasing the heat may burn the onions before their natural sugars develop properly.Dietary Information
This version uses vegetable broth and cheeses made with microbial or vegetarian rennet. Traditional Parmesan and some Gruyère cheeses contain animal rennet and therefore do not meet a vegetarian diet. Check the bread, broth and cheese labels for nut warnings when preparing the soup for someone with a nut allergy.Nutrition Information
The original estimate of 320 calories per serving is too low for the stated quantities. The recipe contains 300 g of cheese, which contributes more than 300 calories to each serving before adding the bread, onions, butter and olive oil. The revised estimate is approximately 560 calories per bowl. Sodium varies considerably according to the broth, bread and cheese brands.Variations
Use beef broth for a more traditional variation, but the soup will no longer be vegetarian. For a lighter topping, reduce the total cheese from 300 g to 200 g. A small splash of dry white wine can be added after caramelizing the onions.Storage
Refrigerate the soup without the bread and cheese in an airtight container for up to 3 days. Reheat it until steaming hot, then add freshly toasted bread and cheese. Store the bread separately to prevent it from becoming soggy.Wine Advice
A lightly oaked Chardonnay complements the sweet onions and melted cheese. A light Pinot Noir also works well without overwhelming the soup. Explore suitable wines at René’s Wijnbeleving.Nutrition values
Serving: 1 bowl with cheese toast | Calories: 560 kcal | Carbohydrates: 37 g | Protein: 28 g | Fat: 35 g | Saturated Fat: 19 g | Sodium: 1250 mg | Sugar: 11 g