Kyanite

Nothing in this list is craftable in turn, so one Kyanite is a single step: 4 units of material drawn from 2 base items, plus 3 crystals.

That bill outweighs 3,935 of the 13,602 recipes tracked here and 504 of the 2,216 Goldsmith ones, and 9,374 recipes nest deeper.

Both raw materials are gathered, and no spot for either is timed, so nothing in the tree waits on the Eorzean clock.

Kyanite is itself consumed by 19 further recipes, spanning five of the eight crafting classes.