Viral First Contact Stew
In this dream I was watching a cooking show. It was like a 'science of cooking' type thing. The guy presenting was making Viral First Contact Stew. Somehow a mathematical equation had proved that any hostile aliens would be allergic to the same things we're allergic to, while benevolent aliens would tolerate these foods well. Therefore, First Contact Stew, which the presenter assured us had gone viral, was a safeguard against alien invasion. You could offer this stew to the aliens and they would suffer a fatal anaphylactic reaction. At some point he used the phrase 'highly allergenic foods'.
The stew, which was not actually stew at all, consisted of walnuts, shrimp, and chunks of mango and tomato. Raw potato chunks were added at the end 'to really sock it to em'. All this was cooked in a pan with some water and no spices.