Add the flour and salt to a food processor and pulse. Then add butter and pulse until the mixture resembles coarse meal. Add grated cheese a little at a time and pulse.
Add water, one tablespoon at a time, until the dough forms into a ball. Continue pulsing between tablespoons - this could take a minute. You can also feel the dough and if it shapes into a ball, it is ready.
Flatten between two pieces of wax or freezer paper, and chill for 10-20 minutes. This helps the butter get cold and makes for a puffier cracker.
Roll the dough fairly thin. About 1/8 of an inch is a good thickness. More thin = crispier, but you don't want it paper thin.
Cut out shapes and place on a baking sheet.
Bake at 350 degrees F for 12-20 minutes depending on how thick your crackers are.
Store in an airtight container for up to 1 week.