1) Preheat the oven to 180°C / gas 4.
2) Take a sharp knife and trim and pull off the top layer of fat, most of which will pull away. Disregard the fat. With a small sharp knife, peel off the sinew.
3) Place the oil in the pan and when hot, hold the bones of the lamb and lay it down into the pan moving it around the oil while holding onto the bones. Turn it over until it gets an all over nutty colour and take off the heat.
4) Mix the honey and the mustard together in a bowl.
5) Mix the rosemary, thyme and pinhead oats together.
6) Place the seared lamb on a chopping board and brush on the honey mustard all over and place the lamb onto the herbal mix, moving it around so it is wholly coated in the mix.
7) Place the potatoes, celeriac and fennel in a bowl, add the cream, Parmesan, parsley, chilli, garlic and salt and mix together. Place in the oven for 30-40 minutes. When the vegetables have been in the oven for 20 minutes, place the lamb in the oven. Remove both after a further 20 minutes.
8) Place the lamb stock and the red wine in a pot and bring them up to the boil, and gently cook them down by two-thirds. Add mint jelly and stir it around with a whisk.
9) Serve up the vegetable dish and lamb rack on a plate and pour some gravy on top.