If time permits, spread lamb with mustard mixture up to one day ahead. Keep covered in the fridge. Remove lamb 20 minutes before cooking.
2.2kg leg of lamb, bone in
1⁄4 cup Dijon mustard
1 tblsp olive oil
3 cloves garlic, crushed
1 tblsp finely chopped fresh rosemary
2 tsps fennel seeds
Salt and pepper, to taste 2 cups chicken stock
HERB CHILLI DRESSING
1⁄2 cup chopped fresh parsley
1⁄2 cup chopped fresh mint
1⁄3 cup lemon juice
1 medium green chilli, deseeded, finely chopped
1 tblsp Dijon mustard
2 tsps honey
Place lamb in a large, oiled, roasting pan. Combine the mustard, oil, garlic, rosemary and fennel in a small bowl. Spread over top of the lamb. Season with salt and pepper.
2 Cook in a hot oven (200C) for 25 minutes. Remove pan from oven. Reduce oven to moderate (180C). Carefully add stock to the pan. Return to oven.
3 Cook, basting lamb with cooking juices halfway through, for a further 45 to 50 minutes until medium done, or until cooked to your liking. Remove. Rest lamb, loosely covered with foil for 30 minutes.
4 Just before serving, make dressing. Combine all ingredients in a jug. Season. Mix well.
5 Spoon dressing over lamb. Cut into slices.