Ingredients :

• Salmon with skin — Choose thick, center-cut fillets with the skin on. It forms a natural barrier between the fish and the bottom of the parcel — preventing sticking and protecting the flesh during steaming. You might not eat it, but it does its job.
• White miso (shiro miso) — This is the mildest, least salty miso. It can be found in Asian grocery stores or organic sections. If you only have red or mixed miso, start with one tablespoon and taste the paste before spreading — red is much more powerful and can easily become overwhelming.
• Kewpie Mayo — This is the Japanese mayo in a tube with the pointy red cap. It’s rounder and slightly sweeter than classic mayo, with a real umami depth. In the recipe, it binds the miso and keeps the salmon moist. If you can’t find it, mix regular mayo with a few drops of rice vinegar. Not identical, but it does the job.
• Shiitake and shimeji — Shiitake brings a woody, almost smoky note. Shimeji is more delicate, with a texture that remains slightly firm even after cooking. Together, they absorb the salmon’s cooking juices. You can replace them with button mushrooms — you just lose a bit of that depth.