This was an impromptu attempt to use up some turnip greens. I guess it is a kind of ohitashi.
1 small bunch turnip or other greens
Boil until done to your liking, drain and chop
2 tbsp white miso
1 tbsp mustard powder
about 1 tbsp mirin or cooking water, to smooth the sauce
mix this together until smooth and mix in with the chopped greens
This much mustard powder makes it very hot. You could cut back.