To make the pastry, process the flour (or flour and semolina, which gives it extra crunch) and butter, then add the sugar, followed by the beaten egg and just enough water (about 2 tbsp) to form a dough. Shape into a disc, wrap in cling film and leave to rest in the fridge for 20 mins.
Meanwhile, to make the filling, place the sugar, ground almonds, butter, egg and egg yolk in a bowl and mix to make a creamy paste. Stir in the kirsch or Armagnac. Chill for at least 20 mins.
Heat oven to 190C/fan 170C/gas 5. Roll the pastry out onto a floured surface and use to line
a 23cm loose-bottomed tart tin. Fill with lightly greased foil and baking beans and bake for
20-25 mins, removing foil after 15 mins, until golden. Spread the almond paste onto the base of the pastry and bake for 25 mins until golden and crisp. When the tart comes out of the oven, arrange the cherries on top in a single layer. Heat the cherry conserve with 1 tbsp water until smooth, then brush over the cherries. Leave to cool before removing from the tin. Cut into wedges to serve, adding a spoonful of crème fraîche if you like.