I happened to see this post and my contribution is macaroni & cheese with jelly, hummus, or peanut butter. I had a few of those sandwiches when I was vacationing with friends some years ago and said friends were all grossed out; I was just starting on vegetarianism (but not veganism) back then, and I had trouble thinking of food at the beach house that was both readily available and easy to make. I think the peanut butter version wasn't as good... which, uh, makes sense, especially in retrospect.