Classic French Onion Soup Recipe

I absolutely adore this recipe because it transforms basic ingredients into a comforting, restaurant-worthy dish that’s perfect for cozy nights in. The magical combo of caramelized onions and melty Gruyère on top of crispy baguette slices makes it feel like a warm hug for my taste buds!

The rich flavor of Classic French Onion Soup, with its warm depth of comfort, is something I love. The slow-cooked sweet yellow onions, blended with both butter and olive oil, create an aroma in the air that’s hard to resist.

Adding dry white wine and fragrant thyme makes this soup sing, a real note of perfection at the finish line with a cheesy, glazed, toasted French baguette. Perfect for elevating a cozy night in.

Ingredients

• Yellow Onions: Rich in antioxidants, they bring sweetness when caramelized.
• Unsalted Butter: Adds richness; moderate dairy fat content.
• Dry White Wine: Introduces acidity; enhances flavor depth.
• Beef Stock: Base for umami; provides minerals and protein.
• Fresh Thyme: Aromatic herb; offers earthy notes and antioxidants.
• French Baguette: Provides carbohydrates; classic texture for topping.
• Gruyère Cheese: Nutty, melty topping; source of calcium and protein.

Ingredient Quantities

• 6 large yellow onions, thinly sliced
• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 1 teaspoon sugar
• 1 teaspoon salt
• 1/2 cup dry white wine
• 8 cups beef stock
• 2 sprigs fresh thyme
• 1 bay leaf
• Salt and pepper to taste
• 8 slices of French baguette
• 2 cups grated Gruyère cheese

Instructions

1. In a big pot, combine the butter and olive oil and heat them up over medium heat. Toss in the onions, sugar, and salt and cook for about 30 to 40 minutes, giving the mixture a good stir every now and then, until the onions are a deep, rich, golden brown and caramelized.

2. After the onions are caramelized, add the dry white wine and scrape up any browned bits from the bottom of the pot. Allow the wine to reduce for about 2 to 3 minutes.

3. Include the beef stock, the thyme sprigs, and the bay leaf in the pot. Let the soup reach a simmer and cook it for 30 minutes to let the flavors marry.

4. As the soup simmers, set the oven to 400°F (200°C) to preheat. Place the baguette slices on a baking sheet and toast in the oven until they are a deep shade of golden brown, about 5 to 7 minutes.

5. Take out the bay leaf and thyme from the soup. Taste the soup and add salt and pepper to it if it needs adjusting. Season to taste.

6. The broiler should be set to preheat. The soup is then poured into bowls that can go in the oven. The bowls need to have some room left at the top so that the bread and cheese can fit in nicely, without overflowing.

7. Lay a slice of toasted baguette on top of each bowl of soup. Grate Gruyère cheese and lavish it over the bread.

8. Set the bowls on a baking sheet and place in the oven under the broiler until the cheese is melted and bubbly, about 3 to 4 minutes.

9. Remove the baking sheet from the oven and allow the bowls to cool for a minute or two.

10. Serve the hot French onion soup, if desired, with a little extra thyme as a garnish. Enjoy it for the rich, savory flavors, and the gooey cheese topping!

Equipment Needed

1. Large pot
2. Wooden spoon or heat-resistant spatula
3. Measuring spoons
4. Measuring cup
5. Knife
6. Cutting board
7. Baking sheet
8. Oven-safe bowls
9. Grater
10. Oven
11. Broiler

FAQ

• Can I use red onions instead of yellow onions?Although yellow onions are thought of as the traditional choice due to their balanced sweetness, red onions can be used too, but will impart a slightly different flavor.
• What can I use as a substitute for the beef stock?Using chicken or vegetable stock as an alternative will yield a lighter flavor profile.
• Is there a substitute for Gruyère cheese?Indeed, you can use Swiss cheese or Emmental cheese as a stand-in, which will still provide a comparable creamy, nutty taste.
• Can I make the soup without wine?Certainly, it is possible to leave out the wine altogether and substitute it with a non-alcoholic white wine. White wine vinegar can also be utilized in the same manner as a non-potable white wine, with a more aqueous form of vinegar offering the most reliable pathway to the end goal of imbuing the food with acidity. Here is a direct substitution for the wine (or Acidity Aficionado Vinegar) you might find in the recipes:

  Omit the wine (or vinegar, as the case may be) and serve up the food with a side of acid in one of the following forms:

  1. A non-alcoholic white wine substitute. (There are a number of products out there.)
  2. White wine vinegar (used as instructed below).
  

• How do I store leftovers?Let the soup cool before transferring it to an airtight container. It can then be stored in the refrigerator for no more than three to four days. The best way to reheat it is on the stovetop.
• How can I make this soup vegetarian?Use vegetable stock instead of beef stock, and make sure any wine used is vegetarian.

Substitutions and Variations

If you can’t find yellow onions, you can use red or white onions instead, which will give a different flavor but the same texture.
Instead of unsalted butter, try substituting ghee or a plant-based butter alternative when you want a deeper flavor or have a dietary preference that keeps you from eating butter.
Canola oil or grapeseed oil can be used in place of extra virgin olive oil if necessary.
Substitutes can be used in place of dry white wine, including dry vermouth or an alcohol-free white wine.
If there is no beef stock, use chicken stock or vegetable stock in its place for a different taste profile.

Pro Tips

1. Caramelization Mastery Patience is key when caramelizing the onions. Lower the heat if necessary to prevent burning, stirring them often to achieve a uniform, deep golden brown color for maximum sweetness and depth of flavor.

2. Wine Options Use a dry white wine such as Sauvignon Blanc or Chardonnay for a subtle acidity that complements the sweetness of the caramelized onions. If you prefer an alcohol-free option, replace the wine with a little more beef stock and a splash of apple cider vinegar or lemon juice for brightness.

3. Bread Choice Try using day-old or slightly stale French baguette slices. They’ll soak up the soup without becoming too mushy, maintaining a delightful texture under the melted cheese.

4. Enhanced Beef Stock For a richer flavor, consider using homemade beef stock or enhancing store-bought stock by simmering it with additional beef bones, garlic, and herbs for an hour before using it in the soup.

5. Herbal Garnish Twist To elevate presentation and aroma, finely chop fresh thyme or parsley and sprinkle it over the melted cheese just before serving for a burst of freshness and color.