French Onion Soup

Bring out the yellow onions and peel them.

Rinse the onions, then halve them. Slice each half thinly.

To a pot on medium-low heat, add butter and olive oil.

I prefer to use a good quality olive oil for this recipe.

Allow the butter to melt.

Once the butter has melted, add in the thinly sliced onions.

Next, add in sugar. Adding sugar to onions helps accelerate and enhance the caramelization process.

Mix until the onions are coated in the butter. Stir every now and again to prevent the onions from burning.

You want to caramelise the onions low and slow – this will take up to 50 minutes. Be patient.

In the meantime, prepare the herb sachet. I used a strainer so it will depend on what you have on hand.

Add rosemary, thyme and bay leaves.

In short: Using a sachet is like brewing tea—you extract all the flavor, then take the bag out before serving. It’s a classic technique in French cooking that helps keep your soup both flavorful and refined.

Next, prepare the beef stock (broth). I used 3 sachets of Woolworths liquid broth.

Add it to a jug and pour in 750ml of boiling water (250ml per sachet).

Stir and set aside until ready to use.

After 40 minutes of sautéing the onions, they should be deeply golden, soft, and jammy with a rich, sweet aroma.

Add in crushed garlic.

Stir and sauté for a further 10 minutes.

After 50 minutes of sautéing, the onions should be deeply caramelized—dark golden brown.

At this point, add in flour. French onion soup traditionally has a brothy base, but adding a small amount of flour after caramelizing the onions gives it a light body—not too thick, just enough to coat the spoon slightly.

Mix and cook out the flour for a minute.

Traditionally, dry sherry is used in French onion soup for its nutty, slightly sweet complexity. But here’s the thing—I’m not really a wine person, and I didn’t have sherry on hand. So I used a can of Merlot, which had lovely notes of red berries, cherries, and even a touch of mint. And you know what It totally worked.

The Merlot brought a fruity depth and a soft richness to the soup that played nicely with the sweetness of the caramelized onions. It’s a bit of a twist on the classic, but that’s part of the fun—making it your own.

Pour in the red wine.

Stir and allow it to cook out for a minute. If you do not want to use alcohol, you may skip the wine, but keep in mind the soup won’t have the same depth and complexity that the wine adds. You can boost flavor by using extra herbs, a splash of vinegar, or a bit of balsamic for a subtle tang instead.

Stir in the prepared beef stock (broth) and Worcestershire sauce.

Adding Worcestershire sauce to French onion soup isn’t traditional—but it’s a clever and effective twist that can really enhance the flavor.

Now it’s time to add salt and pepper to taste, mix well and then add in the herb sachet or strainer.

Cover and simmer for 15 minutes,

After 15 minutes, remove the herbs, gently stir and remove the soup off the heat.

Pick a fresh, crusty baguette from your bakery or store. Day-old bread also works well—it toasts nicely and holds up under the melted cheese.

Using a serrated knife, slice the baguette into about 1/2-inch-thick slices. Aim for uniform thickness so they toast evenly.

Throw in those baguette slices and toast until golden on each side – add more butter if needed.

Now that the baguettes are done toasting, ladle the soup into an oven safe bowl. You may also spoon the soup into small ramekins – depending on your serving portions.

Top the soup with the toasted baguette slices.

Classic French onion soup (Soupe à l’oignon gratinée) is traditionally topped with Gruyère—it’s what gives the dish that unmistakable bistro-style finish. Gruyère melts smoothly without becoming oily or stringy, creating that golden, bubbly, slightly crispy crust on top of the soup. Always grate the cheese yourself from a block—it melts better than pre-shredded cheese (which often contains anti-caking agents).

After toasting baguette slices, generously sprinkle grated Gruyère on top. I got the Gruyère from Woolworths.

Place the bowl into the oven and broil or grill for 3–5 minutes at 225°C or until the cheese is melted, golden, and slightly crisp.

Finish with a sprinkle of finely chopped French chives for a fresh, mildly oniony note that brightens the rich flavors of the soup.

French Onion Soup is more than just a recipe—it’s an experience. The slow-cooked onions, hearty broth, and melted cheese create a dish that’s rustic, elegant, and endlessly satisfying. Whether it’s snowy outside or you just need a little extra comfort, this classic will never disappoint. Bon appétit!

To store this French Onion Soup – Refrigerator: Store the soup (without bread or cheese) in an airtight container for up to 4–5 days. Freezer: The soup base freezes well for up to 3 months. Let it cool completely before freezing, and thaw overnight in the fridge before reheating. Reheat: Warm gently on the stovetop over medium heat. Toast fresh baguette slices and add cheese just before serving for the best texture.