Set a heavy-bottomed Dutch oven or deep soup pot

Add butter and olive oil, then toss in the sliced onions and sprinkle them with sugar.

Cook the onions gently, stirring every few minutes, for about 40 to 50 minutes. They’ll go from translucent to golden, and then deep amber brown. The goal is slow caramelization, not frying.

💡 Tip: If the onions start sticking or browning too fast, reduce the heat and add a splash of water or wine to deglaze. This releases all that flavorful fond (the caramelized bits) and prevents bitterness.

Once your onions are beautifully golden and jammy, pour in the red wine. Stir well, scraping the bottom of the pot with a wooden spoon to lift up all those caramelized bits.

Let the wine simmer for 3 to 5 minutes, just until slightly reduced and fragrant.

Add beef stock, garlic, thyme, bay leaf, and Worcestershire sauce (if using). Bring the soup to a gentle boil, then reduce heat and let it simmer uncovered for 30 minutes.

This is where the flavor deepens, and your kitchen starts smelling like a Parisian bistro at midnight.

Season with salt and black pepper to taste.

While the soup simmers, slice your baguette into thick rounds and toast them until golden. You can use a toaster oven, grill pan, or your oven set to 180°C (350°F) for about 5 minutes per side.

You want them crisp enough to stay firm once you float them on the soup.

Ladle hot soup into oven-safe soup bowls (like the Le Creuset Stoneware French Onion Soup Bowls

Place one or two toasted baguette slices on top of each bowl, then cover generously with grated Gruyère or Emmental cheese.

Place the bowls on a baking sheet and set them under the broiler for 2 to 3 minutes, or until the cheese melts, bubbles, and turns beautifully golden. Keep an eye on them — the transformation happens fast!

Carefully remove from the oven (they’ll be sizzling hot), and let them cool just slightly before serving.

Garnish with a pinch of fresh thyme or cracked pepper if you like.

Serve immediately with a glass of wine, a light salad, or just good company.