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+ servings
4.41 from 10 votes
French Onion and Leek Soup
Prep Time
15 mins
Cook Time
1 hr 25 mins
Total Time
1 hr 40 mins

Rich, hearty broth, crunchy bread and gooey cheese make this bowl of french onion and leek soup pure comfort food goodness.

Course: Soup
Cuisine: French
Keyword: french onion leek soup, french onion soup
Servings: 6 servings
Calories: 544 kcal
  • 3 Tbsp unsalted butter
  • 2 lbs onions, sliced into half moons
  • 1 lb leeks, white and pale green parts, sliced into half moons, and washed thoroughly
  • 4 oz shallots, diced (about 2 large)
  • 2 cloves garlic minced
  • 2 Tbsp Wondra flour (or AP fkour)
  • 1 Tbsp light brown sugar, packed
  • 1 Tbsp sherry vinegar
  • 1 1/2 cups dry white wine
  • 1 quart beef stock
  • 1 Tbsp fresh thyme, minced
  • 1 bay leaf
  • kosher salt and freshly ground black pepper
  • 2 Tbsp port
  • 1 baguette, sliced and lightly toasted
  • 8 oz gruyere thinly sliced or grated
  1. Heat the butter over medium heat in a dutch oven or a large heavy-bottomed pot.

  2. Add the onions and a dash of salt and cook over medium heat for 15 minutes. The onions should be very soft and pale golden.

  3. Add the leeks, shallots, and garlic and continue to cook for an additional 15 minutes, stirring often. The mixture should be very soft and golden.

  4. Reduce the heat to low, stir in the flour, and cook for 2 minutes. Add the light brown sugar, vinegar, and a pinch of salt and cook until onions are a deeply golden and very soft, an additional 15 mins.

  5. Add the wine, bring to a boil, and then reduce to a simmer. Be sure to scrape up all the brown bits from the bottom of the pot as you deglaze with the wine.

  6. Pour in the stock and stir in the thyme, bay leaf, salt and pepper (to taste). Cover and simmer for 30 mins.

  7. Add the port and simmer uncovered an additional 5 mins.

  8. Slice the baguette into rounds and lightly toast in the oven or a toaster.

  9. Ladle the soup into oven safe bowls or crocks, top with a couple of rounds of toasted baguette and slices or a good sprinkling of the grated gruyere.

  10. Turn your broiler up to high and broil the tops until melted and golden brown. Serve immediately.

Nutrition Facts
French Onion and Leek Soup
Amount Per Serving
Calories 544 Calories from Fat 180
% Daily Value*
Fat 20g31%
Saturated Fat 11g69%
Cholesterol 57mg19%
Sodium 723mg31%
Potassium 838mg24%
Carbohydrates 59g20%
Fiber 6g25%
Sugar 15g17%
Protein 22g44%
Vitamin A 1849IU37%
Vitamin C 24mg29%
Calcium 527mg53%
Iron 4mg22%
* Percent Daily Values are based on a 2000 calorie diet.