cookery vs boil down

cookery is a noun but boil down is not a noun.

Word	Noun	Adjective	Verb	Adverb
cookery	Yes	No	No	No
boil down	No	No	Yes	No

cookery (noun)	boil down (noun)
the act of preparing something (as food) by the application of heat

cookery (verb)	boil down (verb)
	cook until very little liquid is left
	be cooked until very little liquid is left
	be the essential element