French Onion Soup

Slowly caramelized onions, homemade veal stock, and simple ingredients make this a meal to remember.

A stretch of cool, rainy weather in Luxembourg felt more like October than the end of August, making it the perfect time to make soup.

I had been looking forward to making soup with the veal stock I made a few months earlier. I had used it in other dishes, but soup was always high on the list. Cool temperatures, rain, and soup made for a cozy dinner at home.

French onion soup is made with simple ingredients, but it cannot be rushed. The onions need time to slowly cook down and develop their deep, sweet flavor.

I slowly caramelized the onions, deglazed the pot with sherry, and added garlic, fresh thyme, and rosemary. Toasted baguette and plenty of Gruyère finished each bowl.

I served the soup with a simple mixed green and radish salad dressed with a Dijon, honey, and garlic vinaigrette. The soup was rich, comforting, and worth every minute it took to caramelize those onions.

What I Used

Serves approximately 4, with one cup per serving

  • 632 g onions, thinly sliced
  • About 30 g unsalted butter
  • Salt
  • About 120 ml dry sherry
  • 3 garlic cloves
  • Several sprigs of fresh thyme
  • 1 sprig of fresh rosemary
  • 1 1/2 liters homemade veal stock, reduced to 1 1/4 liters
  • Freshly ground black pepper
  • 1 small baguette, sliced
  • Olive oil
  • 1 garlic clove for the toast
  • About 200 g Gruyère, shredded

The Method

Caramelize the Onions

Melt the butter in a heavy pot over medium low heat.

Add the sliced onions with a small pinch of salt. Cook slowly, stirring regularly, until the onions collapse and become deeply golden and caramelized. Add a small splash of water whenever the onions begin sticking to the bottom of the pot.

This takes time. Let the color of the onions guide you rather than the clock. Mine took about 2 1/2 hours.

Prepare the Baguette

While the onions are cooking, lightly brush both sides of the baguette slices with olive oil. Rub both sides of each slice with the cut garlic clove.

Toast until golden.

Shred the Gruyère and set aside.

Build the Soup

When the onions are deeply caramelized, add the garlic, thyme, rosemary, and sherry. Scrape the bottom of the pot and let the sherry reduce by about half. I like the flavor of the sherry in the finished soup, but you can reduce it further if you prefer a more subtle flavor.

Pour in the reduced veal stock. Bring the soup to a gentle simmer and cook for 30 to 40 minutes, allowing the flavors to come together. The soup will reduce to approximately 1 liter, or just over 1 quart.

Remove the herb stems and garlic cloves. Taste and season with salt and freshly ground black pepper.

Assemble the Bowls

Preheat the broiler.

Ladle the soup into oven safe bowls. Place the toasted baguette slices over the soup and cover generously with shredded Gruyère.

Set the bowls on a baking sheet and place them under the broiler until the cheese is melted, bubbling, and beginning to brown.

Serve immediately with a simple mixed green salad.

From My Kitchen

  • Give the onions plenty of time. Their deep caramelization creates the foundation of the soup.
  • Add a little water if the onions begin sticking. It loosens the caramelized bits without adding more fat.
  • Homemade veal stock gave the soup an especially rich flavor.
  • Reduce the sherry by half to keep more of its flavor, or reduce it further for a subtler result.
  • Place the oven safe bowls on a baking sheet before filling them. This makes them much easier to move in and out of the oven.
  • Watch the bowls closely under the broiler. The Gruyère can go from melted to overly browned very quickly.

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