Sure, it's a break with tradition, but I always find myself wishing for just a little chocolate on Thanksgiving. The dough I'm using here is soft and easy to roll out, but it still turns out tender and flaky. I've used about half the weight of the flour in total fat. For a flaky crust, make sure butter, shortening, and liquids are very well chilled. If you have a hot kitchen, chill your flour, too.
Cold fat creates steam, thus flaky layers.
According to food scientist Shirley Corriher, cold fat melts slowly in the hot oven, giving the dough a chance set on either side of it. When the fat does start to heat up and melt, the resulting steam puffs layers apart, creating flakiness. Shortening, with its higher melting point, helps the fat stay firmer longer. Cold liquid stimulates less gluten formation. Strong gluten is good for bread, but it makes pie crusts tough.