Christmas Pudding

It sits in the top food tier, which is where you want to be before a boss attempt. The catch is the clock: it burns off far quicker than the other foods at that level, so eating one while you build an arena wastes it. Swallow it as the summon goes off, not before.

Presents only show up during the Christmas window, and they are not a generous drop even then. If you want a run supplied with these, farm the season while it is open and stash the puddings, because there is no vendor and no crafting route back to them once the window closes.