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: The painting doesn't have a name, and if it does it is never mentioned in this episode.