Ingredients
Soup Ingredients
- 1 kg onions (approximately 6 medium onions, spiralized)
- 40 g butter
- 2 tsp brown sugar
- 4 cloves garlic (crushed)
- 2 Tbsp plain white flour
- 250 ml dry white wine
- 950 ml vegetable stock or broth
- 2 tsp soy sauce
- 1 tsp marmite
- 2 bay leaves
Garnish and Serving
- A few small sprigs of rosemary (optional, for garnish)
- Baguette slices (2 per serving)
- 1/2 cup grated Gruyere cheese
Instructions
- Prep the onions: Spiralize the onions into long strands, making the cooking and caramelization process easier and quicker.
- Caramelize the onions: Melt the butter in a large, heavy pan over low heat. Add the spiralized onions and brown sugar, stirring to coat everything in the butter. Cover with the lid and cook on the lowest heat for at least 1 hour, stirring every 15 minutes, until the onions are soft, brown, and richly caramelized.
- Add garlic: Stir the crushed garlic into the caramelized onions just until fragrant, about 1-2 minutes.
- Add flour: Sprinkle the plain flour evenly over the onions and stir well to incorporate the flour fully.
- Deglaze with wine: Pour in the dry white wine and increase the heat. Let it bubble gently for a couple of minutes to cook off the alcohol.
- Add stock and seasonings: Add the vegetable stock, soy sauce, marmite, and bay leaves to the pan. Stir to combine.
- Simmer the soup: Reduce heat and simmer the soup for another hour to deepen the flavors or until ready to serve.
- Prepare the toppings: Toast the baguette slices, then top each slice generously with grated Gruyere cheese.
- Serve and finish: Ladle the soup into bowls, place two cheese-topped baguette slices on top of each bowl, and grill under a broiler until the cheese is melted, bubbly, and slightly crisp. Garnish with rosemary if desired before serving.
Notes
- Using spiralized onions speeds up the caramelization and breaks down the onions into a softer texture.
- Cooking the onions slowly over low heat is crucial for developing the deep, sweet flavor of caramelized onions.
- If you don’t have marmite, a small amount of soy sauce alone can be used, but marmite adds unique umami depth.
- Use a dry white wine to avoid overly sweet soup; a Sauvignon Blanc or Pinot Grigio works well.
- For a vegan version, substitute butter with olive oil and use a vegan cheese alternative for topping.
- The soup can be made a day ahead; flavors improve after resting overnight.
- Prep Time: 20 minutes
- Cook Time: 1 hour 50 minutes
- Category: Soup
- Method: Stovetop
- Cuisine: French
- Diet: Vegetarian
