1) Start by grating both cheeses.
2) Using your hands or a fork, coarsely mix in your butter with your flour. Shoot for pea-sized lumps. It helps if your butter is chilled.
3) Now mix in all your cheese. Again, use that pastry cutter or your clean fingers to integrate the cheese, flour, and butter well.
4) Add a few tablespoons of ice water to the dough to help shape it. You want to be able to work with it but you don’t want it too moist. I had to add about 4 Tablespoons to my dough before I could work with it.
5) Divide dough into two and wrap these in plastic and let them chill for up to 3 days. You can roll them out right away but they will be easier to work with if they are chilled.
6) Roll dough out onto a floured surface until it’s 1/4-inch thick.
7) Cut dough into squares, strips, or whatever.
8) Lightly grease baking sheets and sprinkle crackers with coarse salt.
9) Bake these guys at 450 for just eight minutes. Ten if you want them extra crispy.