buckwheat
蕎 refers specifically to buckwheat, a plant whose seeds are used to make soba noodles.
蕎 combines the grass radical 艹 with the phonetic component 喬, which likely contributed the sound キョウ. The character was used in Chinese for a type of plant, and in Japanese it came to specifically denote buckwheat.
The grass radical 艹 sits above 喬, like tall buckwheat plants growing in a field.
For キョウ, imagine a buckwheat field in Kyoto: Kyoto -> キョウ, and the buckwheat grows tall under the grass radical.
buckwheat (Fagopyrum esculentum)
soba in soup with slices of boiled fish paste, shiitake mushrooms, greens, seaweed, etc.
soba in hot broth; soba without any trimmings
zaru soba (soba served on a bamboo draining basket with dipping sauce)
soba with broth poured over it
soba eaten at the end of the month (esp. at the end of the year)
soba made with two parts wheat flour to eight parts buckwheat flour
high quality soba
soba with egg
soba with tempura batter
dark soba
buckwheat dumpling; buckwheat mash; buckwheat dough ball
soba dipping sauce
buckwheat cookie
soba restaurant
buckwheat chaff
yabu soba; green-colored soba made from buckwheat flour milled with green buckwheat berry chaff
soba in hot broth, topped with a salty-sweet dried herring