Erwtensoep (Dutch pea and ham soup)

1.Heat 2 tbsp olive oil in a large saucepan over medium heat. Add leeks, celery, onion and garlic, and sauté until very tender (10-12 minutes). Add chopped celeriac, ham hock, smoked ribs, split peas and 3 litres water. Bring to the simmer, reduce heat to low, cover and simmer, topping up with water to keep ham hock covered and skimming off foam from the top occasionally, until ham hock and split peas are very tender (2½-3 hours). Remove hock and ribs and set aside to cool, then shred meat (discard skin, bones and sinew). Purée soup with a hand-held blender, add meat to soup, heat through, season to taste and keep warm.

2.Heat vegetable oil in a deep-sided frying pan or deep-fryer to 160C. Add sliced celeriac and fry, turning occasionally, until golden (2-3 minutes). Transfer to a tray lined with paper towels using a slotted spoon. Season to taste with sea salt flakes and set aside until required.

3.Heat remaining olive oil in a frying pan over medium heat, cook sausages, turning occasionally, until golden (1-2 minutes). Serve scattered over hot soup with celery leaves and snow pea tendrils, and celeriac chips to the side.