1 cup all-purpose flour
3/4 tsp. salt
1/2 tsp. ground pepper (optional)
4 TBSP cold unsalted butter, cut into small pieces
8 ounces grated cheddar cheese
3-4 TBSP water
Pulse the flour, salt and pepper, then add butter and pulse until the mixture resembles coarse meal. Add grated cheese a little at a time until the mixture again resembles coarse meal.
Pulse in 3 to 4 tablespoons of water, one tablespoon at a time, until the dough forms into a ball. It will probably take a minute or so.
Remove, wrap in plastic, and chill for 20 minutes or up to 24 hours. I left mine overnight. This way the butter has time to solidify and I think makes for puffier crackers.
Roll the dough out to 1/8th-inch thickness directly onto a baking sheet. You don't want to roll them paper thin, neither do you want to roll them too thick. If they are too thin, they will not puff up as much. If they are too thick, they will not be as crispy.
Cut the dough into 1-inch strips, then cut into triangles.
Bake at 350° F for 15-20 minutes or until crackers are golden brown. Watch them after the 10 minute mark.