Preheat the oven to 180C/350F/Gas 4.
In a small shallow gratin dish layer the thinly sliced sweet potato, cream and cheese alternatively, reserving some of the cheese to sprinkle on the top.
Cover with foil and bake in the oven for 25 minutes, removing the foil for the last 10 minutes.
In a hot frying pan seal the cutlets on both sides. Brush one side of the chops with mustard.
Increase the oven temperature to 200C/400F/Gas 6. Sprinkle 1 tbsp of the fresh crust on to one side of the lamb cutlets. Don't pat the crust, leave it in a pile.
Place them in an oven for about 3 minutes or until golden brown. In a small pan reduce some lamb stock to serve as a thin gravy.
Take a circular cutter, cut into the gratin and place it off centre on a serving plate. Lay the cutlets alongside the gratin and drizzle a small amount of lamb stock on the plate, eat immediately.