Lamb with mushrooms and fresh truffle

PREPARATION

1. Light the Big Green Egg and heat to 150 °C. Place the celeriac among the coals, close the lid and allow to cook for 15 minutes, turning regularly.
2. Carefully remove the celeriac from the EGG using the Grill Tong and place the grid. Heat a layer of barbecue oil along with the garlic in an oven-proof pan on the grid and allow to cook for approximately 10 minutes.
3. Remove the pan and the grid from the EGG. Place the convEGGtor, replace the grid and raise the EGG’s temperature to 140 °C. In the meantime, debone the lamb’s shoulder or have this done by the butcher upon purchase. Set aside a couple of sprigs of rosemary and thyme, mince half the herbs and chop the rest coarsely. Sprinkle salt, pepper and the minced herbs on the lamb’s shoulder. Roll it up then wrap tightly in aluminium foil. Place the foil-covered roulade on the grid and cook until it has a core temperature of 53 °C.
4. Remove the roulade from the EGG. Remove the grid and the convEGGtor then put in the Cast Iron Grid. Raise the temperature to 150 °C. In the meantime, sprinkle pepper, salt and the coarsely chopped herbs on the lamb’s rack and the fillet or tenderloin, then place on the Cast Iron Grid. Cook both until they reach a core temperature of 53 °C. Remove the foil from the roulade then, when the rack and the fillet or tenderloin have reached a core temperature of approx. 45 °C, return it to the EGG and grill on all sides. In the meantime, brush the mushrooms clean, halving the larger chestnut mushrooms. Cut the celeriac into thick slices and peel these. Remove the garlic from the oil.
5. Remove all the lamb from the grid and allow to rest under aluminium foil. Heat a dash of barbecue oil in an oven-proof pan on the grid and fry the mushrooms in it. Put the celeriac on the grid and give it a nice grill mark on one side. Turn the celeriac slices over, put the garlic and the rosemary and thyme you set aside earlier on the grid and give the other side a good grill mark.
6. Remove the garlic and celeriac from the grid. Cut the celeriac into the desired shape and carefully squeeze the cloves of garlic from their skins. Cut the meat into good slices (save the remaining meat for the following day) and distribute across the plates along with the celeriac, garlic and mushrooms. If necessary, season to taste with pepper and salt, then grate fresh truffle on top.