Ingredients

Yellow Onions

5 large (about 3 lbs), thinly sliced

From: Parisian Golden Onion French Bistro Soup

Unsalted Butter

4 tbsp

From: Parisian Golden Onion French Bistro Soup

Extra Virgin Olive Oil

2 tbsp

From: Parisian Golden Onion French Bistro Soup

Garlic

4 cloves, minced

From: Parisian Golden Onion French Bistro Soup

Dry White Wine

1 cup

From: Parisian Golden Onion French Bistro Soup

Beef Broth

6 cups

From: Parisian Golden Onion French Bistro Soup

Fresh Thyme

6 sprigs

From: Parisian Golden Onion French Bistro Soup

Bay Leaves

2

From: Parisian Golden Onion French Bistro Soup

Worcestershire Sauce

1 tbsp

From: Parisian Golden Onion French Bistro Soup

Balsamic Vinegar

1 tbsp

From: Parisian Golden Onion French Bistro Soup

French Baguette

1 loaf, sliced into 1-inch pieces

From: Parisian Golden Onion French Bistro Soup

Gruyère Cheese

3 cups, freshly shredded

From: Parisian Golden Onion French Bistro Soup

Parmigiano-Reggiano

1/2 cup, freshly grated

From: Parisian Golden Onion French Bistro Soup

Fine Sea Salt

2 tsp

From: Parisian Golden Onion French Bistro Soup

Freshly Ground Black Pepper

1 tsp

From: Parisian Golden Onion French Bistro Soup

Instructionsbookmark_border

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1

Prepare the Onions

Peel and thinly slice the onions evenly using a sharp knife or mandoline. Consistent slices help the onions caramelize at the same rate.

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Chef's Tip

Avoid slicing onions too thin, as they can burn before developing their deep caramelized flavor.

2

Begin Caramelizing

Heat butter and olive oil in a large heavy-bottomed pot over medium heat. Add the sliced onions and a pinch of salt. Cook uncovered for 15 minutes, stirring occasionally, until the onions soften and release moisture.

3

Deeply Caramelize the Onions

Reduce heat to medium-low and continue cooking for 45 to 55 minutes, stirring every few minutes, until the onions become deeply golden brown and jammy. Add small splashes of water if the onions begin sticking.

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Chef's Tip

Great French onion soup depends on patience. Slow caramelization creates the natural sweetness and rich flavor of the dish.

4

Add Garlic and Deglaze

Add the minced garlic and cook for 30 seconds until fragrant. Pour in the white wine and scrape the bottom of the pot to release the flavorful caramelized bits. Simmer for 5 minutes until slightly reduced.

5

Build the Soup Base

Add the beef broth, thyme sprigs, bay leaves, Worcestershire sauce, balsamic vinegar, salt, and black pepper. Bring to a gentle simmer and cook uncovered for 25 minutes to allow the flavors to combine.

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Chef's Tip

A small amount of balsamic vinegar enhances the onions' sweetness and adds complexity without making the soup taste acidic.

6

Prepare the Bread

While the soup simmers, preheat the oven to 400°F (200°C). Arrange baguette slices on a baking sheet and toast for 8 to 10 minutes until crisp and golden.

7

Prepare the Cheese Topping

Combine the shredded Gruyère and grated Parmesan cheese in a bowl. Set aside for assembling the soup.

8

Assemble the Bowls

Remove the thyme stems and bay leaves from the soup. Ladle the hot soup into oven-safe bowls. Place toasted baguette slices on top and generously cover with the cheese mixture.

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Chef's Tip

Using oven-safe bowls allows the cheese to melt directly over the soup for the classic bistro presentation.

9

Broil Until Golden

Place the bowls under the broiler for 2 to 4 minutes until the cheese is melted, bubbling, and beautifully browned. Watch carefully to avoid burning.

10

Serve and Store

Serve immediately while the cheese is hot and stretchy. Store leftover soup without the bread and cheese topping in an airtight container in the refrigerator for up to 4 days. Reheat gently on the stovetop and prepare fresh cheesy toast before serving.

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Chef's Tip

French onion soup often tastes even better the next day because the caramelized onion flavors continue to develop.