Prepare the duck breast by removing the fat and sinew with a sharp knife. Wrap the breast in cling film and place in the freezer
Remove the breast from the freezer when firm and semi-frozen, about 30 minutes. Using a very sharp knife, slice across the breast into thin slices and fan evenly across 4 plates. Cover each with cling film and store in the fridge until required
For the romanesco cauliflower, use the fine setting on a grater to create a cous cous-like texture. Place in a bowl and season to taste with salt and hazelnut oil
To serve the carpaccio, remove the plates from the fridge and allow to stand for 5-10 minutes so they are not too cold. Sprinkle the romanesco 'couscous', some fennel and the cobnuts evenly over the duck. Finish with a small drizzle of hazelnut oil and a sprinkling of chives.