method
1. Preheat the oven to 190°C/375°F. Peel the root vegetables and cut into 1/2 inch cubes. Place in a large bowl, then add the sliced leek.
2. Stir the lemon rind and juice and the mustard into the vegetables and mix well, then season to taste.
3. Cut four 12 inch squares of non-stick baking paper and brush lightly with the oil.
4. Divide the vegetables among them. Roll up the paper from one side, then twist the ends firmly to seal.
5 Place the parcels on a baking sheet and bake for 50-55 minutes, or until the vegetables are just tender. Serve hot with roast or grilled meats.
