Stir the salt with the flour and cut in the lard. I use a pastry cutter or you can use two knives or rub it between your fingers. You want it to look like coarse meal when you are done.
Mix the vinegar with the milk and let stand for a couple of minutes. Give it a stir then add a little bit at a time to the lard/flour mixture. Add enough to make the dough come together into a shaggy ball. Wrap in plastic.
Chill the dough for 30 minutes before using.