In a food processor, combine flour, salt and butter.
Pulse to combine until the mixture looks like coarse meal.
Add shredded cheese, pulse 3 times.
Add 3 Tablespoons ice water and cider vinegar. Pulse to combine, just until the dough is moistened and will stick together when pressed with your fingers.
Turn the dough out on to your pastry board and knead just until it comes together.
Wrap the dough in plastic and refrigerate at least 30 minutes, longer is better.