Preheat oven to 450°.
Coat the bottom of a jelly roll pan with oil.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, pepper, and garlic salt in a large bowl. Add beer; stir well. Beat egg whites with a mixer at high speed until stiff peaks form. Gently fold egg white mixture into flour mixture.
Combine breadcrumbs and parsley in a shallow dish. Working with one fish strip at a time, dip in flour mixture; dredge in breadcrumb mixture. Repeat procedure with remaining strips, flour mixture, and breadcrumb mixture. Place on prepared baking sheet. Lightly coat strips with cooking spray.
Bake at 450° for 15 minutes or until fish flakes easily when tested with a fork. Remove from oven.
Broil the fish sticks 1 minute or until tops are lightly browned. Serve fish sticks with malt vinegar, if desired.