1. Mix dry ingredients in food processor, add seasoning, and gradually add butter until blended.
2. Add milk until dough forms.
3. Move dough to surface and let rest 5 minutes; roll to 1/8" thick and cut 2" pieces.
4. Place on an ungreased baking sheet and lightly brush with egg white; prick with a fork.
5. Bake at 350F for 15 to 17 minutes or until crisp; cool on wire racks.