"I'm going to have pork with tomato, and you?"
Translation:Je vais prendre du porc à la tomate, et toi ?
No because it's wrong. Tomate is feminine so you say à la tomate.
It's very important to remember the gender along with the vocabulary word. For example I wouldn't memorize a plain word like tomate. Instead, I memorize it along with a gender specific modifier like une tomate.
I also try to memorize short phrases like la sauce à la tomate. Knowing that one term reinforces the gender of two nouns, sauce and tomate.
(It also helps when you want to order dinner!)
This isn't really the question that Mackers8 and D.Dominique are asking. Yes, "au tomate" is wrong, but they're asking why you HAVE to use "a" and you can't use "avec, in these cases. I was wondering it myself. Is it because it's just the way that food dishes are expressed in French to make it clear that "du proc a la tomate" is pork prepared with tomatoes, as opposed to "porc avec des tomates" as being a dish of pork with tomates served on the side and separately from the pork?