Recipe for Ika Sansai?
I've checked my books and checked the web, and I too can't find a vetted recipe.
Remember than "sansai" literally means "mountain vegetables", but infers "wild foods of the hills picked in the seasonal resurgence of spring".
Thus: several fern shoots, bamboo shoots, yuki shoots (coltsfoot)...
It is traditionally a springtime dish, one among other springtime uses of sansai, to celebrate the season.
Sushi restaurants buy it frozen for year-round use. If you have a water-packed refrigerated source of sansai, then you could try a simmered dish. Should the flavor be dashi, mirin, soy, ponzu?... could be whatever you choose to simmer with your squid. I can't see that any efforts would be wasted, to be refined the next time.
Lots of folks simply dump some waterpacked sansai into noodle dishes, etc.