I have been reading through Bruce Chilton, A Feast of Meanings: Eucharistic Theologies from Jesus through Johannine Circles (Brill, 1994). The following citation is a significant methodological statement about what he thinks about the eucharistic texts in the New Testament.
Chilton states (pp. 6-7):
"Each of them [that is, the previous views on the eucharistic texts such as those held by Jeremias and others] presupposes that eucharistic texts are best understood as referring simply to the past: Jesus is held to have said and done such and so, and the only issue of importance is whether that is fact or artifice. Each alternative posits a single hero behind the texts, either a willing martyr or a literary genius, who forges meaning in an instant of creativity. The hero acts, and the texts lie inert. But along with their diversity, among the most striking features of the eucharistic texts--especially in the Synoptics, Paul, and the Didache--is their insistence that they relate things to be done, words to be said, and not merely events of the past. They are instruments of practice, not simply matters of record, and their practical dimension is a function of the varieties of practice they both reflect and would promote. Eucharist is a case in which the notion of the New Testament as inert matter (imprinted with something that once happened or was once imagined) is obviously misleading.
"In the case of the eucharist, the texts of the New Testament unmistakably relate practices at least as much as they refer to data.Of course, such may be the position in other instances, as well, but the present concern is not with the documents in general. Rather, critical readings must be guided by the quest to discern those practices within their originating communities which produced texts of eucharist in the New Testament."
Chilton continues on, but his position stated here becomes key for how he proceeds through his argument. As he states, he does not think that one figure, whether Jesus or one of the Gospel writers, was responsible for the eucharistic texts. As he says, it is practice(s) of the eucharist and controversy surrounding it(them) that drive(s) the development of the New Testament record of the eucharist.