Spent Winter Vegetables Cooked in Whey

• About 800 g (1 lb 12 oz) old vegetables, from a selection of lettuce leaves

Place all the raw vegetables in a food processor and purée. Transfer to a pan with the grape seed oil and cook all the vegetables gently for about 45 minutes, without allowing them to colour.

Add the whey or buttermilk and cook over low heat for 2 hours until all the liquid has evaporated. Cool in the fridge and then fold in the sour cream.