Pesachim 36: So Much Unleavened Bread

"Lechem oni" - what does it mean? Why is it used for matzah? (Several different possible explanations) Followed, of course, but what it means to enrich matzah in ways that may make it prohibited on Pesach, in part because additions can make the dough leaven more quickly that water alone does (excepting warm water). Also, why are the kohanim considered more likely to prevent the dough from leavening? Consideration of the diet of the kohanim.