Shojin Ryori means spiritual cooking, but vegetarian cuisine is known popularly in Japan as "meatless cooking" which doesn't sound very spiritual at all. This makes sense, though, because vegetarian cuisine has become so mainstream that many people forget its origin.
It was, in fact, Buddhism that brought vegetarianism out of India, to China, and then to Japan in the 6th to 8th Century. Then, in 9th century, Emperor Saga made a decree prohibiting meat consumption except fish and birds, the origin of fishatarianism, with a little chicken tossed in. But until the advent of Zen in the 13th Century, vegetarianism was practiced by very few in Japan. With Zen, foods made from soy beans like natto, miso and tofu spread via monasteries throughout Japan with other vegetarian practices.
Dashi, the soup base that is a foundation of Japanese culinary arts, is a perfect example of shojin ryori at its most basic. Dashi is normally made with dried bonito flakes and kelp, but as a vegetarian base, the kelp must be of the best quality, simmered not boiled - with high quality dried shiitake mushrooms. Then, the aroma and taste of the kelp blends with the fragrance and sweetness of mushrooms.
Tofu is also shojin ryori - even when done as a kaiseki box with a surprise inside. Picture a block of tofu, opened like a box, and center scooped out. Then, it is stuffed with a very special non-Japanese fungus, and finally quick fried for 30 seconds in a soy bean-olive oil blend. Hamon cannot reveal the secret at the center of the tofu, only to those who wish to try the dish. That is shojin ryori.

精進懐石料理 SHO-JIN KAISEKI
吸い物 Osuimono (soup)
和布入り揚げ豆腐 Wakame iri age dofu - seaweed, tofu dumpling, clear broth
酢の物 Sunomono (salad)
せん切り長芋 若布 胡麻酢 Senkiri nagaimo wakame gomasu - mountain potato, seaweed, sesame dressing
八寸 Hassun (chef’s inspiration)
枝豆南京羹 Edamame nankin yokan - soybean pumpkin
菜 三つ葉 梅肉酢 Junsai mitsuba bainiku su - tre-foil leaf plum
線牛蒡 とろろ昆布焼き Sen gobo tororo konbu yaki - burdock root, seaweed
芥子蓮根 Karashi renkon - lotus roots mustard miso
百合根寒天寄せ Yurine kanten yose -lilly bulb
造り Tsukuri
刺身 盛り合わせ Sashimi Moriawase
口取り Kuchi tori
トリュフ 包み豆腐 Toriufu sumi tofu - truffle tofu
湯葉茶巾 Yuba chakin - soy bean curd
豆腐西京味噌漬け Tofu saikyo miso zuke
焼き物 Yakimono (grilled)
精進握り盛り合わせ Vegetarian nigiri zushi assortment