The arrival in the fields of the bright yellow flowers of nanohana, 'rapeseed blossom', 'rape shoots' or 'field mustard', means just one thing for the Japanese. Spring is here. In reality you can likely find nanohana in department stores from New Year on, but it's the young, fresh yellow flowered plants of spring that are considered best. It is also known as aburana.
Try it in suimono clear soups, sunomono vinagered dishes, with mustard in the 'cooked salad' known as nanohana karashiae, and use it to garnish your fresh sashimi.
You can also try it in a creamy stew with potatoes, mushrooms and onions, with just a hint of miso and/or cheese if it takes your fancy. Beware though that nanohana possesses a distinct, though not overwhelming bitterness, which means it isn't an automatic substitute for Western leafy greens.
Kyoto's nanohana is especially renowned. It grows in the fields of Matsugasaki to the north of the city, where it is made into nanohana shiozuke pickles. The special skills needed to create this ultimate version are a closely guarded secret of a dozen or so local families, even to this day. One old lady who suggested she teach me was threatened with excommunication by the local nanohana mafia all women in their 80s.
When to eat
From the beginning of March through the Spring.
Where to eat
Any ryotei or kappo ryoriya worth its salt.
Yuba Nodoguro Nanohana Ankake with homemade Karasumi Bottarga at Touzentei, Shinmonzen-Yamatooji, Kyoto.