There's nothing special about the pastry recipe - it's the standard shortcrust proportions of fat to flour, enriched with an egg, but after making the pastry by hand (I have no food processor) I followed all his instructions for shaping, resting, rolling and lining to the letter and the results were superb.
I'm sure that cooking the apples in the pastry case before adding the custard filling helped to keep the base crisp, as the apple juices and their glaze made a sticky syrupy layer on top of the pastry, but the way the pastry is handled minimised the usual shrinkage.
As I don't have a pastry ring, I used a loose-based fluted flan tin instead. I don't know whether this was slightly too shallow, or whether my apples were larger than those he used, but I couldn't get all the custard into the case - I only used about 2/3 of the mixture. It looked very pale and wobbly after only 10 minutes in the oven, so I turned off the heat but left the tart in the cooling oven for another 10 minutes, by which time it had coloured slightly. Apart from that, the only other change I made was to use dark rum instead of Calvados - I can't justify buying a bottle for just half a tablespoon!
The finished tart was wonderful - caramelised apples (I used Coxes) which were soft but still holding their shape and not too sweet, held together by a little custard. Together with the aforementioned crisp pastry case, this was just about perfection. My only quibble with the description of perfect was that the cooked custard shrunk away from the apple pieces as the tart cooled. I don't know whether this was because I overcooked the custard or because the tart case was too full - on the TV programme it only looked as if the tart was less than half filled with the custard.