No, it's not a mere accompaniment to a cuppa, but you knew that, didn't you? Cha-kaiseki ryori is the name given to the strictly formalised, painstakingly and artistically crafted cuisine, that is served at a chaji tea function in advance of the tea itself. Cha-kaiseki, as it is commonly called, is the precursor to the more widespread general kaiseki cuisine that is typical of formal dining outside of a tea context, regarded as emblematic of 'Japanese cuisine'.
In Kyoto, the city where cha-kaiseki dining originated, it may be found through the city in restaurants that have no connection with the tea ceremony at all, but its raison d'etre has not changed for centuries. Cha-kaiseki is the cuisine associated with the art and subdued stylistic splendor of the tea ceremony, cha-no-yu.
The essential elements of any cha-kaiseki meal are the ichiju sansai literally" one soup, with three side dishes", plain white rice, plus a suimono clear soup dish, the hassun assortment of delicacies, yuto hot water containing browned rice, and konomono pickled vegetables.
The soup is primarily miso soup, typically using the sweetish shiro-miso 'white miso' of Kyoto. The side dishes are likely to be nimono simmered dishes served piping hot in lacquered, lidded bowls, and yakimono grilled dishes, most often yakizakana grilled fish of some kind. Sunomono vinagered dishes are also common.
Scholars fond of tea and language may be interested to look at the Chinese characters, or kanji, that make up the word 'kaiseki'. It can be can be written in two ways. In Tokyo, the characters for the words ‘meeting’ kai and ‘seat’ seki are often used (会席), but essentially this is a modern coinage.
In Kyoto where it originated, the kanji for ‘inside sleeve’ futokoro, also pronounced kai, and ‘stone’ seki is used (懐石), alluding to the tea ceremony’s origins as a Buddhist rite, when young, novice monks were given small, pebble-sized, heated stones to tuck into the inner sleeves of their kimono, to distract them from gnawing, novitiate hunger. The kanji character for tea is 茶 . Thus, the 'authentic' way to write cha-kaiseki ryori is 茶懐石料理 Don't let anyone try to fob you off with anything else.
Cha-kaiseki is seasonal to the nth degree, and its true practitioners are part-chef, part-visual artist, part-market gardener. Its greatest adepts are found, where else, but in Kyoto.