In a mixing bowl, combine the flour, cayenne, salt, mustard, and butter. Mix until mixture resembles a coarse crumb-like mixture. Add the cheese and mix well. Add the water a tablespoon at a time and let sit for 1 minute. Either using a fork or your hands, carefully press the mixture together forming a soft ball. Wrap in plastic wrap and refrigerate for at least 30 minutes.
Remove the dough from the refrigerator and place it on a lightly floured surface. Roll the dough out on the floured surface into a rectangle 16 by 12 inches in diameter and 1/8-inch thick. Cut the dough into 3-inch by 1-inch strips. Place on a parchment lined baking sheet and bake until golden brown and crispy, about 10 to 12 minutes. Remove from the oven and cool completely.