Aquamarine

Nothing in this list is craftable in turn, so one Aquamarine is a single step: 1 unit of material drawn from a single base item, plus 3 crystals.

That is the lightest raw-material bill on the site, tied with 3,129 other recipes, and 9,374 recipes nest deeper.

Its single raw material is gathered, and no spot for it is timed, so nothing in the tree waits on the Eorzean clock.

Aquamarine is itself consumed by 7 further recipes, spanning two of the eight crafting classes.