What "sauce" is he referring to? Walnut?

Second, the use of the words "tomatoes" and "can."

And "harvest parties???" The thought of that idea coming from a shitstsin like him makes me nauseous and makes my skin crawl.

I know what "can" means. Death, or storage until needed later.

But what about tomatoes?

I feel as if we're missing some of [their] coded language and references.

Thoughts?