French Onion Soup with Gruyère Croutons
Sweet onions simmered in beef stock, ladled into a bowl and topped with toasted baguette and melted Gruyère. A hearty, comforting classic that is not spicy.
- Total
- 60 min
- Prep 10 · Cook 50
- Serves
- 1
- Difficulty
- Easy
You'll practice: Caramelizing · Deglazing
- Savory
- No rush
- French
- Comforting
- Stovetop
- Oven
Instructions
-
Peel the onions, cut them in half and slice thinly, about 3 mm thick. Grate the gruyere and set it aside.
~8 min
Slice the onions evenly so they cook at the same rate and no pieces burn before the rest are golden.
-
Heat 1 tbsp oil in a large saucepan over medium heat. Add the sliced onions and 0.25 tsp salt. Cook, stirring often, until soft and deep golden brown, 25 to 30 minutes. Lower the heat if they start to catch.
~30 min
Slow, patient browning caramelizes the onions' sugars, building the deep sweetness and color that define the soup.
Take the onions all the way to a deep golden brown, not just soft: that browning is where the soup gets its sweetness and depth.
Caramelizing Cook onions low and slow, stirring often, until deep golden brown; rushing with high heat burns them before the sugars develop.
-
Add 2 pinches of thyme and a pinch of black pepper to the onions and stir for 30 seconds. Pour in 400 ml beef stock and scrape up the browned bits. Simmer gently, uncovered, for 15 minutes.
~15 min
Adding stock to the browned pan lifts the fond, the concentrated browned bits that carry most of the flavor.
Deglazing Pour in the stock and scrape the pan bottom firmly to dissolve the browned fond; skipping this leaves flavor stuck to the pan.
-
While step 3 cooks
While the soup simmers, toast the 2 baguette slices on a baking sheet under a hot grill until crisp and lightly golden, 3 to 4 minutes.
~4 min
Toasting the bread crisp keeps it from turning soggy once it floats on the soup.
-
Ladle the hot soup into an ovenproof bowl. Float the toasted baguette slices on top and scatter over the grated gruyere.
~3 min
-
Grill the bowl until the gruyere is melted, bubbling and lightly browned, 3 to 4 minutes. Serve immediately.
~4 min
Grilling melts and browns the cheese, and the bubbling signals the topping is hot and ready.