Stir Cajun seasoning into Basic Marinade until blended.
Place flank steak in a heavy-duty zip-top plastic bag; add marinade mixture. Seal and chill 3 hours, turning occasionally.
Remove steak from marinade, discarding marinade. Cut steak in half lengthwise; cut halves diagonally across the grain into 1/2-inch-thick strips.
Whisk together eggs and hot sauce. Combine flour and next 3 ingredients. Dip steak strips into egg mixture; dredge in flour mixture. Cover and chill 1 hour.
Pour oil to a depth of 4 inches in a Dutch oven; heat to 375°. Fry steak strips in batches 10 minutes or until golden. Serve with Creole Mustard Sauce.