Between Christmas and New Year, we got "uni" sea urchin from Maruhide 丸秀 in Los Angeles, again. We think this is the best place to get quality uni in the U.S. They sell two kinds of uni; one is conventional (treated with potassium alum or myouban 明礬) to maintain the shape and firmness, the other is soaked in 3% salt water (salinity of sea water). The vast majority of uni available, which comes in a tray, is myouban-treated. Done properly, you do not tase the myoban but sometimes, they use an excessive amount and the uni can taste bitter. We got both versions from Maruhide and both are excellent. The one packed in salt water may not last as long as alum-treated one and starts to lose its shape quickly.
I served the myouban-treated uni on the top of perilla leaves and squid sashimi. This is emulating our favorite way to eat uni at Tako Grill (see below).
Since we did not have appropriate squid sashimi, I used a package of precut frozen squid sashimi from the Japanese grocery store.
This uni was alum treated but we did not taste any bitterness and the combination of perilla, squid and uni is indeed our favorite way to eat uni.