gastronomy vs culinary art

gastronomy and culinary art both are nouns.

Word	Noun	Adjective	Verb	Adverb
gastronomy	Yes	No	No	No
culinary art	Yes	No	No	No

As nouns, culinary art is a hypernym of gastronomy; that is, culinary art is a word with a broader meaning than gastronomy:

gastronomy: a particular style of cookery (as of a region)
culinary art: the practice or manner of preparing food or the food so prepared

Other hypernyms of gastronomy include cuisine.

gastronomy (noun)	culinary art (noun)
the art and practice of choosing and preparing and eating good food	the practice or manner of preparing food or the food so prepared
a particular style of cookery (as of a region)