My mother was a great maker of flat Yorkshire puddings. It wasn't one of her party pieces and she knew it!
In the matter of Yorkshire Puddings, as with most things culinary, my bible is Jane Grigson's English Food. One may range far and wide but it's always where I come back to eventually. She is typically discursive on the subject, and the best bit is the "Prize-Winning Chinese Yorkshire Pudding" which originally from the Hong Kong-ish proprietor of a Leeds Chinese restaurant (we're talking 1960s here). who won a proper Yorkshire Pudding competition in Yorkshire. The recipe as given by the cook calls for
300 ml milk
4 eggs
just under ½ teaspoon salt
dash of pepper
½ teaspoon tai luk sauce
250 g sifted plain flour
Beat everything except the flour together, let them stand for 15 minutes, then whisk in the flour. Heat a roasting pan with some juices from the meat to 230°C, then pour in the batter and leave for 20 minutes 52.2 seconds.
This is all rather tongue-in-cheek. Forget the tai luk sauce, there's no such thing (it's a joke at the expense of Yorkshire pride) and don't worry too much about the precision of some of the measurements. The real secret seems to be lots of eggs.
This has always worked spectacularly for me.
Not that I make roast dinners any more. I find them much too heavy for myself and I'd rather take friends to a good carvery since they can work with decent-sized joints, as well as sparing me the cleaning-up afterwards. But I don't mind making a Yorkshire pudding without the roast now and then.