Julia Child French Onion Soup Recipe

Julia Child French Onion Soup is deeply caramelized onions simmered in rich beef broth, topped with crusty bread and melted Gruyère cheese. Julia warns in Mastering the Art of French Cooking (page 43): “You should therefore count on 2½ hours at least from start to finish.”

Two and a half hours. I know. But there’s no shortcut to that deep, sweet, almost jammy onion flavor. Rush it and you get onion soup. Take your time and you get the onion soup.

What is French Onion Soup? A classic French soup (Soupe à l’Oignon) made with slowly caramelized onions in beef broth, topped with toasted bread and melted cheese. The gratinée version broils that cheese until bubbling and golden.

Why You’ll Love This Recipe

• Deeply caramelized onions: Julia’s method cooks onions for 45-60 minutes until they turn an even, deep, golden brown. This slow process develops sweetness and richness that can’t be rushed.
• Restaurant-quality at home: That bubbling cheese crust you get at French bistros? You can absolutely make it happen in your own kitchen with a hot broiler.
• Make-ahead friendly: Julia says you can set the broth aside “uncovered until ready to serve.” Make the base Saturday, gratinée it Sunday.
• Simple ingredients, extraordinary result: Onions, broth, bread, cheese. That’s it. The magic is in the technique.
• Worth every minute: I’ve made quick onion soups. They’re fine. Julia’s version is in a different league entirely.

Julia Child French Onion Soup Ingredients

From Mastering the Art of French Cooking, Vol. 1, Pages 43-45. Serves 6-8.

For the Soup:

• 1½ lbs yellow onions (about 5 cups thinly sliced)
• 3 Tb butter
• 1 Tb oil
• 1 tsp salt
• ¼ tsp sugar (helps the onions brown)
• 3 Tb flour
• 2 quarts beef stock, canned beef bouillon, or a combination of beef and chicken broth
• ½ cup dry white wine or dry white vermouth
• Salt and pepper to taste
• 3 Tb cognac

For the Gratinée Topping:

• 12-16 rounds of hard-toasted French bread (¾ to 1 inch thick)
• 1½ cups grated Gruyère cheese (or Swiss, or a mix with Parmesan)
• 1 Tb olive oil or melted butter

Broth options: Beef stock gives the richest, deepest flavor. Chicken broth works but produces a lighter soup. A combination of half beef and half chicken is a nice middle ground.

Cheese options: Gruyère is traditional and melts beautifully. Swiss cheese works as an alternative. Adding a little Parmesan brings extra sharpness.

How To Make Julia Child French Onion Soup

1. Cook the Onions Slowly: Slice your onions thin. Melt butter with oil in a heavy-bottomed pot over low heat. Add the onions, cover, and let them cook gently for 15 minutes. They’ll soften and release their liquid. Don’t rush this.
2. Caramelize the Onions: Remove the lid and raise the heat to moderate. Stir in the salt and sugar. The sugar helps the onions brown. Cook for 30 to 40 minutes, stirring frequently, until the onions turn an even, deep, golden brown. This is where the magic happens. Your kitchen will smell incredible.
3. Add the Flour: Sprinkle the flour over the onions and stir constantly for 3 minutes. This thickens the soup and removes the raw flour taste.
4. Build the Broth: Remove from heat. Blend in the boiling stock. Add the wine. Season with salt and pepper. Return to heat and simmer partially covered for 30 to 40 minutes, skimming occasionally. Taste and adjust seasoning.
5. Make the Croûtes: While the soup simmers, prepare your bread. Slice French bread ¾ to 1 inch thick. Arrange in a single layer on a baking sheet. Bake at 325°F for about 30 minutes until thoroughly dried and lightly browned. Halfway through, you can brush each side with olive oil and rub with garlic after baking.
6. Finish the Soup: Just before serving, stir in the cognac. This adds depth and warmth.
7. Assemble the Gratinée: Preheat your broiler. Ladle soup into oven-safe crocks. Float the toasted bread rounds on top. Pile grated cheese generously over the bread. Drizzle with olive oil or melted butter.
8. Broil Until Bubbling: Place crocks under the broiler for 1-2 minutes until the cheese is melted, bubbling, and golden brown in spots. Watch carefully. It goes from perfect to burned fast.
9. Serve Immediately: Set each crock on a plate (they’re hot!) and serve right away. Warn your guests the bowls are extremely hot.

Recipe Tips

• Don’t rush the onions. Julia says 30-40 minutes of stirring and browning. Some people try to shortcut this to 10 minutes. It shows. The deep sweetness only comes from patient caramelization.
• The sugar isn’t for sweetness. A quarter teaspoon helps the onions brown more evenly. It’s a technique, not a flavor.
• Use oven-safe bowls. Regular soup bowls will crack under the broiler. Traditional onion soup crocks with handles are ideal. No crocks? Use a large oven-safe casserole and serve family style.
• Toast the bread properly. Soggy bread ruins the dish. Julia bakes hers for 30 minutes at 325°F until completely dried out. It should be hard enough to resist getting soggy in the hot broth.
• Make the base ahead. The soup can be made a day or two before. Store in the fridge. Reheat to a simmer before assembling the gratinée.

Recipe Variations

Soupe Gratinée des Trois Gourmandes (De Luxe Version): Julia includes an even richer variation on page 45. Beat 1 egg yolk with 1 tsp cornstarch, 1 tsp Worcestershire sauce, and 3 Tb cognac. Just before serving, lift the cheese crust, ladle out some soup, and whisk it into the egg mixture. Pour back under the crust and stir gently. Silky and decadent.

What To Serve With This Soup

French onion soup is typically a meal in itself, especially with the bread and cheese topping. If you want to build a fuller menu:

• Simple green salad with vinaigrette balances the richness of the soup.
• Crusty baguette for guests who want extra bread.
• Light dessert like fresh fruit or sorbet. The soup is filling, so keep dessert simple.

Wine: A dry white wine like the one you used in the soup (white Burgundy, dry vermouth) or a light red like Beaujolais pairs nicely.

How To Store

Refrigerator: Store the soup base (without bread and cheese) in an airtight container for up to 4 days. The flavor deepens overnight.

Freezer: Freeze the soup base for up to 3 months. Thaw overnight in the fridge before reheating.

Reheat: Bring the soup to a simmer on the stovetop before adding bread and cheese. Assemble the gratinée just before serving. Don’t try to store assembled soup because the bread gets soggy.

Nutrition Facts

Per serving (serves 8, with bread and cheese):

• Calories: 285 kcal
• Protein: 12g
• Total Fat: 14g
• Saturated Fat: 7g
• Carbohydrates: 26g
• Fiber: 2g
• Sugar: 6g
• Sodium: 890mg
• Cholesterol: 35mg

FAQs

Source: Mastering the Art of French Cooking, Vol. 1 by Julia Child, Pages 43-45

– Claire