For the mint jelly, put the gelatine in a shallow bowl, just cover with cold water and leave for a few minutes to soften. Meanwhile, put the sugar, apple juice and vinegar in a saucepan over a low heat until the sugar has dissolved. Turn up the heat and bring nearly to the boil. Remove the gelatine from the water, squeeze out any excess water, add the gelatine to the pan and stir until dissolved. Set aside to cool. Add the chopped shallot, mint and plenty of salt and pepper, cover and refrigerate until set.
For the lamb cutlets, purée the chicken breast in a food processor (you may need to use a spatula to push the mixture back towards the blades a few times). Add the egg white and blend again. Transfer to a sieve set over a bowl and push through a little at a time using the back of a ladle (don’t use too fine a sieve or you will be at it all day).
Put some ice in a larger bowl and place the bowl containing the chicken over this. Slowly pour in the cream, beating carefully with a spatula until you have a dropping consistency. Fold in the herbs and season well.
Quenelle a good tablespoon of the chicken mixture onto the top of each lamb cutlet, then wrap each one in the pig’s caul. Refrigerate until needed.
When ready to cook, preheat the oven to 200C/180C Fan /Gas 6.
For the sauce Choron, quickly blend the egg yolks, sugar and a pinch of salt in a food processor. In a small pan, heat the lemon juice, wine, wine vinegar and sliced shallot and reduce by half. In another saucepan, melt the butter and allow to bubble. Turn on the food processor again and strain in the hot reduced liquor, followed slowly by the hot butter. Pour the sauce into a bowl, then stir in the tomatoes and tarragon.
To finish the lamb, preheat a frying pan over a brisk heat and add the rapeseed oil and butter. Fry the cutlets on the underside for 2-3 minutes. Transfer to a trivet in a roasting tray and roast for 5 minutes. Leave to rest for 5 minutes, then serve with sauce Choron and mint jelly.