Clue: Kipper in front, farewell forever seafood sandwiches! (3,3,6)
Answer: RIP VAN WINKLE
Explanation: Definition: Kipper
definition: a fictional character who slept/'kipped' for a long time
 **VAN**=vanguard, "front"; sandwiched inside: **RIP** (rest in peace)="farewell forever", and **WINKLE**="seafood"