The One After the Superbowl, part 2 - S2-E13
Chandler: Stick a fork in me, I'm done.
Phoebe: Stick a fork what?
Chandler: You know, like when you're cooking a steak.
Phoebe: Oh, I don't eat meat.
Chandler: Well how do you tell when vegetables are done?
Phoebe: Well you just, you know, you eat them and you can tell.
Chandler: Okay, then eat me, I'm done.
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.