Peel and halve the pears. Remove flower, stalk and core. Bring vinegar, 1/4 liter water, sugar, sliced vanilla pod, lemon peel and cloves to the boil. Add pear halves and cook for about 5 minutes.
Drain the pears, pour into earthenware pots or glasses and pour the vinegar stock over them. Seal tightly with preserving cellophane or parchment paper. Makes 2 glasses of 1/2 liter each.