Lard
Lard is rendered pork fat, the traditional shortening of British pie pastry and the classic fat for hot water crust.
Its large fat crystals produce a flakier, crisper crust than butter alone, with a faint savoriness that suits meat pies. Leaf lard, from around the kidneys, is the mildest grade.
A half-lard, half-butter shortcrust is the old standard for savory pies: lard for texture, butter for flavor.