French Onion Soup

This classic French onion soup recipe transforms average onions and broth into something deeply comforting and savory. It’s made with caramelized onions, savory beef or veal stock, toasted bread and bubbling cheese that brings the restaurant experience to you right at home.

I make this homemade french onion soup recipe with veal stock, which creates a refined broth with exceptional body. Since veal stock is not something most home cooks keep on hand, good beef stock is the practical choice in the recipe. Both work beautifully, and I explain the difference below so you can choose based on what is available or what you make from scratch.

Why this French Onion Soup Recipe is my favorite

How to properly caramelize onions for french onion soup

Caramelized onions should be deeply golden brown, soft and reduced to a fraction of their original volume. They should not merely be sautéed until translucent, and they should not be scorched in an attempt to hurry the process. Use a wide, heavy pot, keep the heat moderate and stir more often as the onions darken. If the bottom of the pan begins to catch, add a tablespoon or two of water and scrape it up before it burns.

Depending on the width of your pot and the moisture in the onions, this stage usually takes 50 to 70 minutes. That is why caramelizing a large batch and freezing it in recipe-size portions is so worthwhile.

Beef Stock vs. Veal Stock for French Onion Soup

Beef stock gives French onion soup a robust, familiar savory flavor and is the easiest choice to find. Choose a low-sodium stock so you can reduce and season the soup without making it overly salty.

Veal stock is milder in flavor but naturally rich in gelatin, giving the broth more body and a silkier finish. It lets the caramelized onions remain the dominant flavor rather than making the soup taste heavily of beef. Use it when you have homemade veal stock or can obtain a good-quality prepared version. You may also combine equal parts beef and veal stock.

The Best Cheese for French Onion Soup

Gruyère is the defining cheese for classic French onion soup. It melts well and contributes a nutty, savory flavor that complements the sweet onions. Mozzarella is milder, but its excellent melting quality creates the generous, evenly browned blanket shown here. Using both gives you the flavor of Gruyère with the melt and coverage of mozzarella.

Use packaged whole-milk mozzarella—not fresh mozzarella, which would release too mcuh water and not produce the stringy result we are looking for. Avoid using pre-shredded cheese which contain non-caking agents that inhibit a good melt.

How to Make French Onion Soup

1. Caramelize the onions. Cook the sliced onions in butter and olive oil with salt over medium-low heat until deeply golden and jammy, 50 to 70 minutes.
2. Deglaze the pot. Add the white wine or dry vermouth and scrape up every browned bit from the bottom of the pot.
3. Build the broth. Add the stock, thyme and bay leaf. Simmer uncovered for 25 to 30 minutes, then season to taste.
4. Toast the bread. Brush baguette slices lightly with olive oil and bake until dry and golden.
5. Assemble the crocks. Ladle hot soup into broiler-safe bowls, top each with toast, Gruyère and mozzarella.
6. Broil and serve. Broil until the cheese is melted, bubbling and browned in spots. Serve carefully; the crocks will be extremely hot.

How to Make French Onion Soup Ahead

For the most useful shortcut, caramelize the onions completely, cool them and freeze them in an airtight container for up to three months. Thaw overnight in the refrigerator or warm them gently in the soup pot before continuing with the sherry and stock.

The finished soup base can also be refrigerated for up to four days or frozen for up to three months. Keep the bread and cheese separate. Reheat the soup until steaming, then assemble and broil the crocks just before serving.

Questions About How to Make French Onion Soup

Homemade French Onion Soup

Christina Collins | Feast & Merriment

Deeply caramelized onions simmer in beef or veal stock, then each crock is topped with toasted bread, nutty Gruyère and melty mozzarella.

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Prep Time 1 hour hr

Cook Time 20 minutes mins

Total Time 1 hour hr 20 minutes mins

Course Appetizer, Main Course

Cuisine American, French

Servings 4 -6 people

Ingredients

  

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• 2½ pounds Vidalia onions halved and sliced ¼ inch thick, about 8 cups
• ½ cup unsalted butter
• 1/2 tsp granulated sugar
• ½ cup dry white wine or dry vermouth
• 4 cups good-quality beef stock preferably low-sodium
• 4 cups good-quality veal stock or 4 additional cups beef stock
• 1 tablespoon Worcestershire sauce
• 1 bay leaf
• 4 sprigs fresh thyme
• 2 teaspoons kosher salt divided, plus more to taste
• ½ teaspoon freshly ground white pepper
• 6 slices rustic bread cut ¾ inch thick and toasted
• 1½ cups shredded Gruyère cheese about 6 ounces
• 1 cup shredded low-moisture mozzarella about 4 ounces

Instructions

 

• Melt the butter in a large, heavy enameled cast-iron Dutch oven, such as Le Creuset, over medium heat.
• Add the sliced Vidalia onions, 1 teaspoon kosher salt and a pinch of sugar. Stir until the onions are thoroughly coated with butter.
• Cook the onions uncovered over medium-low heat for 45 to 60 minutes, stirring occasionally at first and more frequently as they darken. The onions are ready when they are very soft, deeply golden brown and significantly reduced in volume.
• If the bottom of the pot begins to brown too quickly, reduce the heat and add a tablespoon of water. Scrape up the browned bits before they burn.
• Add the white wine or dry vermouth. Scrape the bottom of the Dutch oven to release the caramelized bits and simmer for 3 to 5 minutes, until the liquid has mostly reduced.
• Add the beef stock, veal stock, Worcestershire sauce, bay leaf, thyme, white pepper and remaining teaspoon of salt. Stir and bring to a gentle simmer.
• Simmer uncovered for 30 to 40 minutes. Remove and discard the bay leaf and thyme sprigs.
• Taste the soup and adjust the salt and pepper as needed.
• Position an oven rack approximately 6 inches below the broiler and preheat the broiler. Arrange six broiler-safe soup crocks on a rimmed baking sheet.
• Divide the hot soup among the crocks. Place one piece of toasted rustic bread over each serving, trimming it to fit if necessary.
• Combine the shredded Gruyère and mozzarella. Divide the cheese evenly among the crocks, covering the bread and extending close to the edges.
• Broil for 2 to 5 minutes, watching closely, until the cheese is completely melted, bubbling and browned in spots.
• Let the soup rest for 5 minutes before serving. The crocks will remain extremely hot.

Notes

• Stock: Beef stock produces a robust, classic broth. Veal stock is milder but more gelatinous, creating a silkier texture. A 50/50 blend is excellent.
• Onions: Four pounds looks excessive at first but cooks down dramatically. A wide pot speeds evaporation and promotes even browning.
• Make ahead: Freeze cooled caramelized onions for up to 3 months. Refrigerate the finished soup base for up to 4 days or freeze it for up to 3 months.
• Broiler safety: Confirm that the crocks are broiler-safe. Never place cold ceramic bowls directly beneath a hot broiler.

Keyword comfort food

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