Fold a paper towel in half twice and lay a piece of konbu on top. Sprinkle an even layer of salt down on the kelp and lay each piece of uni on top in a single layer until you've gotten half way through the uni, or you're out of space. Sprinkle another even layer of salt on top of the uni and cover with another piece of kelp and another folded paper towel. Repeat with more kelp and salt if you have more uni, otherwise put it in the fridge to cure overnight.

When you're ready to serve, get your steamer ready to steam. Put half the uni in a ramekin, or other shallow heat-proof dish and add enough mirin to generously coat each piece. Put it into the steamer for about 5-10 minutes or until the alcohol has burned off and the uni is cooked.

When it's done, take the cured uni out of the fridge and gently mix with the steamed uni. Serve a small amount to each person with a glass of cold sake.