Any word whose phonetic structure, whether through auditory impression or physical shaping of the mouth when saying, evokes imagery similar to the meaning of the word itself, where said meaning is food or eating related.
Any word that sounds the way what it means tastes or feels in the mouth. A taste/texture-specific version of onomatopoeia
An example of an Omnomnomatopoeia could be that "zesty" sounds the way zesty things taste. Also consider chewy, crunchy, delicious, savory, pucker, sauerkraut, munch, slurp, etc.