Prepare the shortcrust pastry: put the 4 kinds of flour in a large bowl with the sugar, egg yolks, softened butter (kept out of the fridge for at least 20 minutes and cut in pieces), grated lemon rind and a pinch of salt. Mix rapidly with your hands until you have a smooth compact ball of dough; wrap it in cling film and let it rest in the fridge for at least 30 minutes.
In the meanwhile, butter and flour the tartlet tins. Take the shortcrust pastry out of the fridge and use a rolling pint to roll it out on your work surface, sprinkled with a little rice flour, until you have a sheet approximately 3 mm thick. Using a round pastry cutter of approximately 14 cm in diameter, cut out disks and line the tins with them; pressing the pastry against the bottom and sides with your fingers, to make sure it adheres well. Roll the rolling pin across the edge of each one to eliminate any excess pastry, and prick the bottoms with a fork so that it doesn’t rise while cooking. Bake the tartlet shells in a preheated oven, at 180 °C, for 12-15 minutes, then take them out and leave to cool complete before turning them out of the tins.
Prepare the filling: use the tip of a sharp knife to slit the vanilla pod open lengthwise, and then simmer it slowly in the milk for a few minutes. In a small, heavy-bottomed saucepan, beat the egg yolks with the sugar until pale and light; continuing to stir, incorporate the corn starch and then, very gradually, the boiling milk (from which you have removed the vanilla pod). Put everything back over a low heat and, stirring all the time, continue to cook until the custard thickens. Turn off the heat and let it cool down completely, taking care to stir from time to time in order to prevent a skin forming on the surface; then put it in the fridge for three quarters of an hour.
Wash the grapes, pat them dry and set aside a few for decoration. Cut the others in half and put them in a small saucepan with 1 or 2 spoonfuls of water. Let them simmer for 2-3 minutes, stirring continuously to avoid them sticking to the pan, then pour them into a strainer and let the liquid drip off.
Over a very low heat, dissolve the honey with one tablespoon of sugar and one of water; when it comes to the boil, continue cooking for a minute and then turn the heat off.
Now you’re ready to complete the “job”: distribute the cooked grapes in the pastry shells, cover them with the custard, dip the whole grapes you set aside in the honey syrup and place them on top of the tartelettes to decorate them.