Green pea and leek soup

• 6 oz (175 g) green split peas
• 2 large leeks
• 1

Soak the split peas overnight and drain. Trim the leeks, cut in half lengthways and wash well, then shred finely, reserving a little of the white part for garnish. Peel and finely chop the onion. Melt the butter in a large saucepan over low heat, add the onion and leeks and fry gently for 5 minutes to soften but not brown. Meanwhile, peel and cut the potatoes in even-sized chunks. Add to the pa