Bistro Onion Soup with Leeks

Indulge in the rich, savory flavors of Bistro Onion Soup with Leeks—a comforting twist on the classic French onion soup recipe. This dish combines deeply caramelized yellow onions and tender, sweet leeks, cooked low and slow to develop a golden, velvety base. Infused with dry white wine, aromatic thyme, and a hearty beef or vegetable broth, the soup is a perfect marriage of elegance and wholesomeness. Topped with broiled Gruyère cheese melted over crispy baguette slices, each bowl offers a delightful contrast of gooey, crunchy, and savory goodness. Ideal for cozy evenings, this easy-to-follow recipe is complete in just over an hour, serving as a soul-warming entrée or an impressive first course. Perfect for fans of French cuisine and comfort food alike!

Nutriscore Rating: 72/100

Prep Time:15 mins

Cook Time:60 mins

Total Time:75 mins

Servings: 4

Ingredients

• 3 tablespoons Unsalted butter
• 2 tablespoons Olive oil
• 3 large Yellow onions
• 2 medium Leeks
• 1 teaspoon Granulated sugar
• 1 teaspoon Kosher salt
• 1 cup Dry white wine
• 6 cups Beef broth (or vegetable broth for vegetarian option)
• 4 sprigs Fresh thyme
• 1 Bay leaf
• 8 slices Baguette, sliced
• 1.5 cups Gruyère cheese, grated
• 0.25 teaspoon Black pepper

Directions

Step 1

Peel and thinly slice the yellow onions. Trim and thoroughly rinse the leeks to remove any grit, then slice them into thin rounds. Set both aside.

Step 2

In a large heavy-bottomed pot or Dutch oven, melt butter and olive oil over medium heat.

Step 3

Add the sliced onions and leeks to the pot. Stir to coat them in the butter and oil mixture.

Step 4

Sprinkle in the granulated sugar and kosher salt. Stir well, then lower the heat to medium-low.

Step 5

Cook the onions and leeks, stirring occasionally, for 25-30 minutes, or until deeply caramelized and golden brown.

Step 6

Deglaze the pot by pouring in the white wine. Scrape up any browned bits from the bottom of the pot using a wooden spoon, then let the wine simmer for 2-3 minutes.

Step 7

Add the beef broth (or vegetable broth), fresh thyme sprigs, bay leaf, and black pepper. Stir to combine.

Step 8

Bring the soup to a gentle boil, then reduce the heat to low and let it simmer uncovered for 20 minutes. Discard the thyme sprigs and bay leaf before serving.

Step 9

Preheat your oven’s broiler to high.

Step 10

Place the baguette slices on a baking sheet. Toast each side under the broiler until golden brown, about 1-2 minutes per side.

Step 11

Ladle the hot soup into oven-safe bowls. Top each bowl with a slice or two of toasted baguette, then generously sprinkle grated Gruyère cheese over the top.

Step 12

Place the bowls on a baking sheet and broil for 3-5 minutes, or until the cheese is melted, bubbly, and slightly browned.

Step 13

Carefully remove the bowls from the oven (they will be very hot!), and let cool slightly before serving. Enjoy your Bistro Onion Soup with Leeks!

Nutrition Facts

Serving size	1333.4 grams (1333.4g)

Amount per serving	% Daily Value*
Calories	1896

Total Fat 43.10g	55%
Saturated Fat 22.50g	113%
Polyunsaturated Fat NaNg
Cholesterol 93mg	31%
Sodium 2274mg	99%
Total Carbohydrate 305.50g	111%
Dietary Fiber 19.60g	70%
Total Sugars 37.50g
Protein 40.30g	81%

Vitamin D 0IU	0%
Calcium 324mg	25%
Iron 16mg	89%
Potassium 1642mg	35%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 21.9%

Protein: 9.1%

Carbs: 69.0%