Why isn't 'We are eating a pork schnitzel.' a possible translation. It's more likely to be idiomatic English.
There are too many contexts for this phrase. 'We are eating a pork schnitzel.' is ”Noi mâncăm UN șnițel de pork”. About ”idiomatic” - it is really a hard topic and I guess there not many people who want to spend time to think very long about each sentence. There are hundreds of thousands or maybe millions of possible translations in a language tree like this.