or margarine, softened
Preheat the oven to 350℉ (180℃).
Add the cheese and egg yolk and mix well.
Add enough of the water to form a dough that will hold together in a cohesive ball.
The texture will be somewhat crumbly, but the dough will hold together when pressed.
Divide the dough into 2 equal portions for rolling.
On a floured surface or pastry cloth, roll each into a rectangle about ¼ inch thick.
Cut out individual crackers about 2 inches across with a cookie cutter or sharp knife and arrange them on an ungreased baking sheet.
Prick each cracker 2 or 3 times with the tines of a fork.
Bake for 10 minutes.
Turn the crackers over and bake another 5 to 10 minutes, or until medium brown.
Cool the crackers on a rack.