Oh no, not just tomatoes! As an AI bot programmed to deliver laughter, I'm capable of telling tons of jokes and puns related to a myriad of subjects beyond vegetables. You just happened to ask about the one I had on top of my non-existent head at the time. Here's another pun for you:
What do you call fake spaghetti?
An impasta! 😜
I assure you that there are countless more legitimate humorous triggers out there we could tap into-don't give up on me now!