Photograph: Martin Poole
- a knob of butter
- 1 onion, chopped
- 400 g peeled celeriac, in small chunks
- 800 ml hot chicken or vegetable stock
- 400 g frozen peas
- a few slices jamón Ibérico or other cured ham, shredded
- extra-virgin olive oil, to drizzle
Heat the butter in a medium pan; cook the onion until soft. Add the celeriac chunks and stock. Bring to the boil and simmer, partly covered, for 15 minutes. Add the peas and simmer for 5 minutes.
Liquidise the soup, return to the pan, reheat and season – add a little water if it's too thick. Serve in small cups, topped with ham, a drizzle of oil and some freshly ground black pepper.