Seven Herb Rice Gruel
七草粥 nana kusa kayu means "Seven herb rice gruel" but that is just a part of the story.
These seven varieties of 草 kusa or herbs, also include some 采 sai or na (brassica) which are nutritious and something we should all eat a lot more of.
One thought was that after indulging in all kinds of delicious New Year foods, on this day, people would welcome something so very simple. Our bodies, of course, prefer veggies, and a lot of veggies. We are not particularly well equipped for indulgence. Speaking of equipped, we are more prone to survive poverty than opulence. From a long-term perspective, humans can deal with having less, but not with having more. Fat, sugar, meat and less exercise are not what we are used to.
I like how the seven herb rice gruel is a reminder of that.
A quick google search for nana-kusa-gayu in Japanese gives 593,000 results.
Boil seven types of fresh herbs and roots*
* If you can grow them, here are seven great-tasting herbs and roots that we enjoy this time of year, early January, fresh from our fertile fields in Japan:
Some English names for the above plants are Water dropwort, Shepherd's purse, Cudweed, Chickweed, Nipplewort, turnip and radish. I like how the Swedish word ört (herb) has been incorporated as "wort" in English. Vikings from Scandinavia brought a lot to Britain...
Meanwhile, here in Japan, supermarkets continue to sell special sets on this day, which include all the usual seven veggies.
Here is a google image search result for that!