1. For the celeriac sheets: Slice the celeriac whole into thin sheets (as thin as possible). In a pot of boiling salted water, cook the celeriac sheets for three minutes (until soft and malleable). Drain the boiling water off and run the celeriac under cold water until cooled.

2. For the filling/to assemble: Gently heat the cream in a pot, and add the cheese. Mix with a wooden spoon until fully melted. Take off the heat and when slightly cooled, add the egg yolk, a pinch of salt and pepper and mix together.

3. Lay the celeriac sheets flat and fill with the cheese mix. Fold over in half and roll into a cigar shape.

4. In a pan, heat the butter and add the mushrooms. Cook until golden brown and add the balsamic vinegar and the chopped parsley. Gently place the filled celeriac into the pan with the mushrooms and add a dash of water. Allow to emulsify for three minutes.

5. Slide the cannelloni on to a plate and spoon the remaining mushrooms on top. Garnish with watercress leaves, pepper and a little sea salt. Top with a sprinkling of ready-made crispy onions.