British Style Onion Soup Recipe

Peel and thinly slice the onions. Aim for even 3–4 mm slices so they caramelize uniformly.

In a heavy-bottomed large pot or Dutch oven, heat the butter and oil over medium heat until foam subsides. Add the sliced onions and a pinch of salt.

Cook the onions slowly, stirring frequently, for 30–45 minutes. After 15 minutes add the sugar to encourage caramelization. Reduce heat as needed so the onions brown slowly and do not burn.

When the onions are a deep golden brown and jammy, increase heat to medium-high and deglaze the pan with the white wine, scraping up fond from the bottom. Let the wine reduce by half (~2–3 minutes).

Add the beef stock and demi-glace to the pot along with thyme sprigs, bay leaves, Worcestershire sauce, vinegar, and the remaining salt and pepper. Bring to a simmer, then reduce heat to low and simmer gently for 20–25 minutes to let flavors marry.

Taste and adjust seasoning with salt, pepper, or a splash more vinegar or Worcestershire if needed. Remove thyme sprigs and bay leaves before serving.

Preheat oven to 160°C (325°F). Pat short ribs dry and season all over with kosher salt and black pepper.

Heat olive oil in a heavy ovenproof skillet or Dutch oven over medium-high heat. Sear the short ribs on all sides until deeply browned, about 3–4 minutes per side. Transfer ribs to a plate.

Add the chopped shallot and smashed garlic to the pan and sauté briefly until translucent, about 1–2 minutes. Stir in tomato paste and cook 1 minute to cook off acidity.

Pour in the 300 ml beef stock, scraping up browned bits. Return short ribs to the pan, add a thyme sprig, cover, and transfer to the oven. Braise until tender, about 2 to 2.5 hours.

When ribs are fork-tender, remove from oven. Transfer ribs to a cutting board and shred or slice meat into bite-sized pieces. Skim fat from braising liquid and reserve ~2–3 tablespoons of the reduced liquid to fold into soup or spoon over served portions.

Keep braised meat warm and fold a small amount (about 2–3 tbs) into the finished soup bowls when plating or place on top of the crouton as described below.

Preheat broiler (grill) to high or oven to 220°C (425°F) if using broil function with a rack near the top.

Make the rarebit mixture: In a small saucepan, melt 1 tbs butter over low heat. Whisk in Dijon mustard, Worcestershire, milk, grated cheddar and 100 g Gruyère until a smooth, slightly thickened sauce forms. If too thick, add a splash more milk. Season with black pepper.

Stir in black truffle oil and taste; adjust seasoning. The truffle oil is strong so use sparingly.

Brush both sides of the bread slices lightly with melted butter and place on a baking sheet. Toast under the broiler or in the oven until golden and crisp, about 1–2 minutes per side—watch closely to prevent burning.

Spoon a generous layer of the hot cheese mixture onto each toasted bread slice. Top each with additional sliced/grated Gruyère (from Finishing & Garnish) and place under the broiler until the cheese bubbles and browns lightly, about 1–2 minutes.

Remove and let rest 1 minute; the rarebit crouton should be saucy and melting.

Ladle the hot onion soup into shallow soup bowls or crocks, filling each about 80% full.

Place one truffled Welsh rarebit crouton on top of each bowl of soup. Spoon a few tablespoons of the shredded braised short rib onto the crouton (or into the soup beside it) so meat is warm and melds with the cheese.

Finish with a light drizzle (about 1/8 tsp) of extra truffle oil if desired and scatter microgreens or chopped parsley over the crouton for freshness.

Serve immediately while cheese is bubbling and soup is hot.