Lamb Noisettes with Pak Choi Mash

Soak dried mushrooms in a bowl of hot water for about 20-30 minutes, or until tender, then chop. Cook potatoes in a pan of boiling salted water until tender. Cut fillet into 8 noisettes. Heat vegetable oil in a wok or large frying pan. Add finely chopped root ginger, chopped garlic, 5 spice powder and cook gently for a few minutes to soften. Add diced red pepper and stir fry for a minute. Add peppercorns and chopped mushrooms. Add red wine, jus and chicken stock and reduce and season. Add butter. Cook lamb. Sweat chopped pak choi in 1oz butter. Mash potatoes, then add pak choi and butter and season. Place cooking ring on a plate and spoon the mash into ring to fill. Remove cooking ring and top tower of mash with a noisette. Arrange remaining lamb noisettes around the plate and pour over the sauce.