This is a simplified version of the classic French-cut, slowly caramelized onion soup. It blends methods from Serious Eats, Chef John, Andrew Rea, Joshua Weissman, and others.
Mechanic
The flavour comes from the fond: onions cooked low and slow for an hour or more until deeply browned, with the brown layer scraped off the bottom of the pot again and again before it burns. Traditionally the soup uses a homemade veal or beef stock, but it also works well with a Rich veg/mushroom stock.
Soup
- 1 bag (1.3 kg / 3 lb) yellow onions
- 1–2 large white onions
- 2 leeks
- 1–2 shallots
- 2 tbsp butter
- 2 tbsp olive oil
- 2 sprigs thyme or sage
- 1 bay leaf
- ½ cup (120 ml) dry sherry, such as Amontillado
- or white wine plus a splash of cider vinegar
- or bourbon plus white wine
- 2 L stock of your choice, ideally a darker one (veal, beef, mushroom, roasted chicken)
- salt and pepper
Thinly slice the onions, leeks, and shallots. Put them in a large pot or Dutch oven with the butter and olive oil over medium-low heat. Cook, stirring regularly, until deeply browned, 1–1½ hours. Scrape the fond off the bottom each time you stir so none of it burns, and add more butter or oil if the onions start to stick.
Deglaze with the sherry (or substitute), scraping with a wooden spoon until all of the fond is lifted. Add the stock and herbs, and simmer for 20–30 minutes.
Season with salt and pepper. Remove the herb stems and bay leaf, and take the pot off the heat.
Crusty bread
- 1 baguette, cut into 2 cm slices
- olive oil
- 1–2 garlic cloves, halved
Heat the oven to 220°C (425°F). Rub the bread with the cut garlic, brush lightly with oil, and toast until golden. The broiler is faster, but don’t walk away or it will burn.
Assembly
- about 100 g cheese per portion, usually Gruyère or similar
Ladle the soup into individual oven-safe bowls or a larger casserole dish. Set the bread in the soup, half submerged. Top with the cheese and broil until bubbling and browned. Don’t walk away from it; it goes from browning to sadness quickly.
Notes
- A pressure cooker can handle the first phase: cook the sliced onions with the fat at high pressure for 20–25 minutes, with a soft release, then cook uncovered, stirring, until the liquid is gone and the onions brown. The stovetop method is best.
- Unless you have access to a great commercial stock (there aren’t many good ones), make your own. It really makes the dish shine.