Honey dijon racks with potato and kumara gratin

1.Combine oil, mustard, vinegar, garlic and honey in large bowl, add lamb, turn to coat all over in marinade. Cover, refrigerate 3 hours or overnight.

2.Preheat oven to moderately hot (200ºC/180ºC fan-forced). Grease deep 19cm-square cake pan.

3.Using V-slicer, mandoline or sharp knife, cut kumara and potatoes into 2mm-thick slices, place half of the kumara slices, overlapping slightly, in prepared pan. Top with a layer using half of the potato, overlapping slices slightly. Repeat layering with remaining kumara and potato.

4.Blend flour with a little of the cream in medium jug to form a smooth paste, stir in remaining cream and milk. Pour cream mixture over potato and kumara. Cover gratin with foil, cook in moderately hot oven about 45 minutes or until vegetables are tender. Uncover gratin; sprinkle with cheese. Cook, uncovered, in moderately hot oven about 15 minutes or until cheese browns lightly. Stand gratin 5 minutes before serving.

5.Meanwhile, drain lamb, reserve marinade. Place lamb on wire rack in large shallow baking dish, cook, uncovered, in moderately hot oven for about the last 35 minutes of gratin cooking time or until cooked as desired. Cover to keep warm.

6.Bring reserved marinade to a boil in small saucepan. Reduce heat, simmer sauce, uncovered, 5 minutes. Serve gratin with lamb, drizzled with sauce.