French onion soup

Introduction

Onion soup is simple luxury when the ingredients are good. Start with plenty of onions, sliced evenly for consistent caramelization.

Use good olive oil, preferably extra virgin, because this is not supposed to fry hard. Once most of the onions are in the pot, continue with garlic, fresh thyme, and a sharp white wine.

This needs browning. And when you brown onions, it has to happen over a long time. You may think you are done after an hour, but keep going. That is the only way to get the full sweet depth out of the onions.

Then move on to good stock. Here I like a mix of chicken stock and beef stock.

While the soup simmers, set the oven to 220 °C (430 °F) and toast the baguette. Once the soup is ready, top with a generous layer of sharp melting cheese. If Gruyère is unavailable, use the best local blend you can find.

Step-by-step

Ingredients (serves 4)

• 1.5 kg yellow onions (3.3 lb), thinly sliced
• 3 tbsp extra virgin olive oil
• 25 g butter (2 tbsp)
• 4 garlic cloves, finely chopped
• 6 sprigs fresh thyme
• 1 bay leaf
• 250 ml dry white wine (1 cup)
• 750 ml chicken stock (3 cups)
• 750 ml beef stock (3 cups)
• 1 tsp salt, plus more to taste
• 0.5 tsp black pepper
• 1 baguette
• 120 g aged white cheese (4 oz), grated or sliced thinly

Method

1. Heat the olive oil and butter in a large pot over medium-low heat. Add all the onions with a little salt. The onions should soften slowly, not fry aggressively.
2. Cook gently, stirring now and then, until deeply golden, sweet, and almost jammy in their own juices, 75 to 100 minutes.
3. Stir in the garlic, thyme, and bay leaf, and cook for 2 minutes. Pour in the white wine and reduce until the pot is nearly dry again.
4. Add the chicken stock and beef stock. Bring to a simmer, lower the heat, and cook gently for 25 to 30 minutes. Season with the remaining salt and black pepper. Remove the thyme sprigs and bay leaf.
5. Set the oven to 220 °C (430 °F). Slice the baguette and toast it for 6 to 8 minutes, until dry and golden.
6. Ladle the soup into ovenproof bowls or a small baking dish. Top with baguette slices and cover with the cheese.
7. Gratin under high heat in the oven or under the broiler until the cheese bubbles and picks up dark spots, 5 to 8 minutes. Let the bowls sit for a couple of minutes before serving.

Serving Notes

• If you only have one kind of stock, that works, but the chicken-and-beef mix gives you more depth without making the soup heavy.
• A dry Riesling alongside makes complete sense here, and a simple green salad is enough on the side.
• Do not rush the browning. The entire dish depends on the onions getting the time they ask for.