"Big Mac in Time": what if a time traveler took a Big Mac to ancient Rome?

I was pondering the way modern society takes for granted the availability of high-calorie, flavor packed fast food: how in many ways those foods are way *more* flavorful than anything that existed before, and how, therefore, something as quotidian as a Big Mac would have likely blown the culinary mind of an ancient Roman.

So, to expand on the title question: suppose a time traveler brought a nice, fresh, hot Big Mac (presumably in some sort of stasis field device to keep it hot. Don't overthink it.) to the emperor Vitellius, Galba, or any similarly foodie-oriented 1st century CE emperor, and said "Give me gold and I will teach you how to make this." (Or, I suppose, "Da mihi aurem et te docebo quomodo hoc facere.")

In what ways do you speculate history would be different, these two millennia hence, had the emperor taken the deal?

(And lest anyone quibble about unavailability of modern ingredients--e.g. no tomatoes, so what about the ketchup--let us give our time traveler the benefit of the doubt and presume they have come up with reasonable substitutes or ways to make things from scratch. E.g. groundcherries are an old world plant with high glutamates and a similar flavor profile to tomatoes that would make an adequate ketchup.)