Pumpkin and Chestnut Soup, from the Aveyron from Sud de France by Caroline Conran

Ingredients

• 1 small onion, chopped
• ½ stick celery, chopped (keep the leaves)
• 3 strips lemon peel, chopped
• 4 sage leaves
• 300 g fresh chestnuts peeled (see below) or use vacuum packed chestnuts
• 3 tbsp olive oil
• 1 litre chicken stock
• 250 ml single cream or milk
• salt, pepper
• 1 leek, white part only, chopped
• 500 g pumpkin or acorn squash, peeled and diced
• 1 bay leaf