Onion Soup

Have you ever tried the legendary French Onion Soup Au Gratin? This iconic dish has a fascinating history that dates back to Louis XV, who popularized it in French high society. Made with caramelized onions, house made meat-based stock, and a touch of wine, this comforting soup is topped with toasted bread and melted cheese for a truly indulgent experience. The secret to a perfect onion soup lies in the slow caramelization of the onions, which enhances their natural sweetness and depth of flavor. Whether you prefer to use white wine or red wine, the key is to simmer the soup gently for hours to develop rich, savory notes that will tantalize your taste buds. If you're looking for a classic bistro soup that exudes warmth and sophistication, then French Onion Soup Au Gratin is the perfect choice. Treat yourself to a bowl of this traditional dish and let its luxurious flavors transport you to the heart of French culinary excellence.

Please note that the full access to this content needs a subscription: please sign up.

A French treasure

This recipe is a protected and only available for paid members. To obtain the full step by step recipe and detailed ingredients list, please sign up.

Preview the recipe

About Alcohol Substitution

Finding ingredient substitutions for a recipe can be a risky balancing act. For example, even though the alcohol burns off during cooking, wine itself is difficult to truly replace. In onion soup, wine brings so much depth and complexity. To compensate for its absence, you can use more stock or perhaps a 1:1 ratio of stock and natural grape juice, and the addition of a splash of red wine vinegar to deglaze the cooked onions. The overall taste won't be the same, but it's a reasonable compromise.

Stock

First, blanch the meat. Place the shanks in a large pot and cover with cold water. Bring to a boil, skim off any scum that rises to the surface, then drain. Return the meat to the empty pot and add 3.5 quarts (or liters) of water, along with the leek, carrots, and salt. Bring to a boil, then cover and cook on low heat for 2.5 hours. Strain the liquid and use it in place of stock for the onion soup. Reserve the cooked meat from the shanks for later use.

Mise-en-Place

Peel the onions and cut them into thin slices. If using demi-glace, mix 750 ml of demi-glace with 2.5 quarts (or liters) of water.

Cooking Onions 1

In a Dutch oven or heavy-bottomed pot, cook the onions with butter over high heat for 5 minutes, stirring occasionally. Add salt, pepper, chopped garlic (if desired), thyme, and bay leaves. Cover and cook for 20 minutes on high heat. (Covering the pot at this stage encourages the release of moisture.) Remove the lid and reduce the heat to low. Continue to cook for about 2.5 hours, stirring every so often. As the onions cook, they will turn brown and develop a sweet, caramel-like aroma.

Cooking Onions 2

Pour in the port and red wine. Simmer gently for about 2 hours, allowing the liquid to reduce until fully evaporated and the onions start to caramelize once more. Stir from time to time.
Add the demi-glace and water (or stock). Bring to a boil, then reduce the heat to low and cook for about 30 minutes. Discard the herbs and adjust the seasoning with salt and pepper to taste.

Croutons

The acidity of a sourdough pain de campagne is the best match for an onion soup that is on the sweet side. Preferably, use bread that is 2 days old. Cut it into 1-inch (2.5 cm) thick slices, then cut those into cubes (small cubes are better than large ones). Toss the cubes with olive oil and toast them in the oven for about 10 minutes at 400°F (200°C)

Gratiner

Heat the onion soup and preheat the salamander or broiler. Fill the bowls with the hot soup and add a few croutons (go easy on them, or they will soak up too much liquid). Top with both cheeses and grate some Parmigiano-Reggiano over the top. Place the bowls under the broiler or salamander for a couple of minutes, until bubbly and the cheese is lightly browned. Bon appétit!

Storage

Onion soup can be kept refrigerated in sealed containers for up to 4 days or frozen for up to 6 months.

Ready to discover this recipe? You're only 1 step away.

This recipe is only accessible to registered members!

Create your account to access all recipes and content of my website.

Join us now and enjoy more 800 recipes (Mostly French with European Influences, American Classics and Asian fusion)

Sign up now

Already register? Sign in

Want to see more tasty recipes?

The kitchen is an incredible playground where every ingredient, every recipe, every flavor, is both a destination and a path to new discoveries. I always try to introduce you to new taste horizons through my recipes. Did you enjoy this one? If so:Do you know my incredible Velvet Celery Soup recipe? Don’t miss my Corn Soup step by step video recipe. Let’s also try this one: Broccolini Soup.