For the fenugreek oil:
Combine the seeds and oil in a vacuum pack and heat at 70ºC (158ºF) for 3 hours. Leave to cool naturally and leave at room temperature for a minimum of 3 weeks prior to using.
For the chicken terrine:
Preheat the oven to 100ºC (212ºF). Joint the wings and place them in a baking tray. Cover with fenugreek oil and confit in the preheated oven for 3 hours or until soft. Remove the wings from the oil and, while still warm, pick off all the meat. Pack 750g of the chicken meat into a lined terrine mould or similar. Dissolve the gelatine in the hot chicken stock and pour it over the chicken, ensuring it works its way into any gaps. Wrap the terrine with clingfilm (plastic wrap), weight it heavily and refrigerate overnight or until firm.
For the fenugreek mayonnaise:
Combine the egg yolks, mustard and vinegar and slowly whisk in the oil. Season with salt and lemon juice then fold in the chives.
For the truffle:
Brush the truffle to remove any dirt or impurities, then shave it into nice large slices.
To serve:
Carefully unmould the chicken terrine and cut into rectangular pieces. Place a dollop of mayonnaise on each piece of terrine, then build ‘sandwiches’ using the truffle slices as if they were bread, so you have mayonnaise-topped chicken between 2 slices of truffle. Season with salt and serve.