Combine flour, butter, salt and red pepper in bowl; beat at medium speed until dough forms. Add cheese; mix until ball forms. Shape dough into disk; wrap in plastic food wrap. Refrigerate 2 hours or overnight.
Heat oven to 350°F.
Roll out dough on lightly floured surface to 1/4-inch thickness. (It will be hard to roll at first, but will soften. Press together any cracks that form on edges of dough.) Cut dough with 1 1/2-inch cookie cutters or pizza cutter into desired shapes. Place onto ungreased baking sheets.
Beat egg white and water together in bowl. Brush cut-outs with egg wash; sprinkle with seeds.
Bake 14-16 minutes or until lightly browned around edges. Immediately loosen from pan; let cool on pan.
Shortbread can be topped with a variety of other ingredients such as chili powder, seasoned salt, fennel seed or herbs.