Preheat the oven to Gas mark 5, 190°C, 375°F.
In a small bowl mix together the oil, orange juice, thyme, garlic and Chinese 5 spice.
Put the vegetables in a large non-stick roasting tin, season and spoon over half the citrus mixture. Lightly shake the pan to spread out and coat the vegetables.
Place the joint on a chopping board, make several slits over the surface and season. Position the lamb on top of the vegetables and roast for 25-30 minutes.
Remove from the oven, spoon the remaining citrus mixture around the vegetables and brush the marmalade over the joint and vegetables. Return to the oven and continue to cook for a further 10 minutes.
Remove from the oven with the vegetables and transfer to a warm plate, cover with foil and leave to rest for 5-10 minutes. Carve the lamb and serve with the vegetables.
1 x 350-400g (12-14oz) lean lamb mini roasting joint (thick flank or topside)
Salt and freshly milled black pepper
For the Citrus Vegetables:
30ml/2tbsp rapeseed or olive oil
45ml/3tbsp freshly squeezed orange juice
Small bunch fresh thyme leaves
4 garlic cloves, peeled and finely crushed
10ml/2tsp Chinese 5 spice powder
400g/14oz baby carrots, cleaned and trimmed
400g/14oz baby new potatoes, halved
45ml/3tbsp thick cut Seville orange marmalade, warmed
Extra thyme leaves, to garnish