French Caramelized Onion Soup with Gruyère Baguette

Slice 750 g onions 5 mm thick. Melt 40 g butter and 10 ml olive oil over medium-low heat in a heavy pot; add onions and 3 g salt and cook 35–45 minutes, stirring frequently, until deep golden but not burnt. Lower heat if scorching.

Stir in 15 g flour for one minute, then gradually whisk in 1100 ml low-sodium beef broth to prevent lumps. Add 5 g thyme, one bay leaf and 1 g pepper; bring to a simmer.

Simmer uncovered on low for 20–25 minutes until onions are soft and broth flavors deepen. Remove thyme stems and bay leaf; if overly reduced, add water 50 ml at a time.

Preheat oven to 210°C. Slice 120 g baguette into four pieces and toast for about five minutes until dry and crisp. Grate 140 g Gruyère and divide into four equal portions.

Place four ovenproof soup crocks on a baking sheet and ladle in hot soup. Float one baguette slice on each, top with 35 g cheese, and bake on upper oven rack 4–6 minutes until bubbly and golden. Remove with mitts and cool five minutes before serving.