I think you should blind bake the pastry, or your tarts will be soggy.
All you need to do is roll out the pastry into the dish, and then rest it in the fridge for 20 min. Pull off a sheet if foil or baking paper that is larger than your dish, and put it on top of the pastry. Pour some rice or dried beans on top of the foil or paper. Bake for 15 minutes at 200C, then remove the foil / baking paper and the rice/ beans and then cook for another 5 min, until golden.
Then pour in custard and bake as per the recipe.