Caramelised Onion & Mature Cheddar Soup

• 900 mlgood chicken or vegetable stock
• 1 tbspplain flour
• salt and black pepper
• 1.2 kgwhite onions, peeled and thinly sliced
• 2sprigs fresh thyme
• 1 tspsoft brown sugar
• 50 gunsalted butter
• 1 tbspolive oil
• 1 tspDijon mustard
• 200 mldry cider
• 150 gmature cheddar, coarsely grated
• 4thick slices sourdough, about 50g each
• 1leek, finely sliced

Method

1. 1Melt the butter and olive oil in a large heavy pot over medium-low heat. Add the onions and leek with the brown sugar and a generous pinch of salt; season now, while the onions can absorb it, not at the end when they've already set their flavour. Cook, stirring every 5–10 minutes, for 50–60 minutes until everything is deeply caramelised, jammy and a rich mahogany brown, with sticky bits catching on the base of the pot. Don't rush this; pale onions taste of nothing, and this slow surrender is where the whole soup's flavour lives.
2. 2Stir in the flour and Dijon mustard and cook for 2 minutes, scraping the sticky fond up from the base as you go; the raw flour smell should disappear and the paste should darken a shade. Pour in the cider, let it hiss against the hot pot, and bubble hard for 3 minutes to cook off the alcohol and lift every last caramelised scrap off the bottom.
3. 3Add the stock, thyme. Bring to a gentle simmer and cook for 25 minutes, stirring occasionally. Fish out the thyme stalks.
4. 4Take a stick blender to roughly half the soup directly in the pot; you want a silky, glossy body with plenty of soft onion strands still running through. Taste: salt to wake the sweetness, black pepper for warmth.
5. 5Meanwhile, heat the grill to high and toast the sourdough slices on one side until golden. Flip, pile the cheddar generously on top, and grill until bubbling, blistered and golden at the edges; watch it, the line between molten and burnt is about 30 seconds.
6. 6Ladle the hot soup into warmed bowls, float a cheesy cheddar toast on each and finish with a heavy crack of black pepper at the table.

Per serving

kcal

578

protein

20.5g

fibre

8.5g

carbs

60.1g

fat

28.3g