Rub butter into flour and salt until the mixture resembles breadcrumbs, then stir in sugar.
Mix in egg yolks to form a dough, adding water if needed.
Divide dough into two portions and knead orange zest into one portion.
Wrap dough portions separately and chill for 30 minutes.
Beat mascarpone, lemon juice, icing sugar, and cream until thick and refrigerate.
Simmer stoned cherries with sugar and kirsch until tender, then cool.
Preheat oven to 190°C.
Roll dough, cut into 24 circles, and bake in greased tart tins until golden.
Melt chocolate and dip 12 whole cherries into it to set for garnish.
Heat whipping cream and pour over remaining melted chocolate to create a ganache.
Fill plain tart cases with cooked cherries and top with chocolate ganache.
Pipe mascarpone filling into orange tart cases and top with red berries.