Preheat the oven to 375°F (190°C)
Mix 3 cups all-purpose flour with 1 teaspoon salt
Add about 1 cup water gradually until a stiff dough forms
Knead the dough briefly until smooth
Roll the dough out to about 1/4 inch thickness
Cut into squares or rectangles
Prick each piece several times with a fork
Place pieces on an ungreased baking sheet
Bake for 30 to 40 minutes, flipping once halfway through
Reduce the oven to 250°F (120°C) and bake longer if needed until very dry and hard
Let cool completely before storing