before I cannot make custard, but G can, luckily.
Bill has a neat trick for the pastry rounds - you layer 2 slices of defrosted pastry on top of one another, roll it up, slice it and then roll the spirals out into pastry rounds for tart shells.
Anyway, simple enough concept. Make custard on stove top, allow to cool. Pour into unbaked pastry shells, bake together. Sprinkle with icing sugar JUST before you serve or it will dissolve.