Beat the egg yolks with 20g sugar in a large bowl. Place the gelatine leaves in a bowl of cold water to soften.
Place the milk in a saucepan and bring to the boil.
Heat a frying pan and add the remaining 100g sugar. Melt, without stirring, to obtain a golden caramel. Add the fleur de sel and stir in gently. Pour the hot milk into the caramel, mix well and then add this mixture to the egg yolks. Return to the heat to obtain a thin custard. Remove from the heat and stir in the gelatine leaves. Pour the mixture in to a syphon and chill.
Place all the crumble ingredients in a bowl. Rub together with the tips of your fingers to obtain a crumble. Spread out on a baking tray and bake in the oven for 10-15 minutes.
Preheat the oven to 180°C.
Peel the apples, remove the core and slice. Place the apples slices in a baking dish.
Place the sugar in a frying pan and melt, without stirring, to form a caramel. Once you have a golden caramel, add the butter, tonka bean, crushed peppercorn and the vanilla pod. Add the water a little at a time, mix well, then pour the caramel over the apples. Transfer to the oven and cook for 40 minutes.
For the caramel: add the caster sugar to a frying pan and melt, without stirring, to form a caramel. Once you have you have a dark caramel, add the salted butter and then gradually add the cream. Mix well and then allow to cool.
Attach the gas canister to the syphon. Place the apples in the base of deep plates or soup bowls. Syphon on a little of the caramel emulsion, sprinkle with the crumble and finish with a drizzle of the caramel sauce.
«Feel free to replace the tonka bean with a long peppercorn - this will also work well in this recipe but the flavours are not at all the same.»