chop-suey greens vs greens

chop-suey greens and greens both are nouns.

Word	Noun	Adjective	Verb	Adverb
chop-suey greens	Yes	No	No	No
greens	Yes	No	No	No

As nouns, greens is a hypernym of chop-suey greens; that is, greens is a word with a broader meaning than chop-suey greens:

chop-suey greens: succulent and aromatic young dark green leaves used in Chinese and Vietnamese and Japanese cooking
greens: any of various leafy plants or their leaves and stems eaten as vegetables

Other hypernyms of chop-suey greens include green, leafy vegetable.

chop-suey greens (noun)	greens (noun)
succulent and aromatic young dark green leaves used in Chinese and Vietnamese and Japanese cooking	any of various leafy plants or their leaves and stems eaten as vegetables
grown for its succulent edible leaves used in Asian cooking