Whisk the spices and spread half of them evenly on the cling film. Place the fish on top, sprinkle with the remaining spices, and let sit in the refrigerator for 48 hours, wrapped in the plastic wrap.
Unwrap and scrape off the spices with a sharp kitchen knife. Cut into tranches of about half a centimeter and drizzle with the best olive oil.
In this maizena (corn starch) the fish flavor develops best.
Serve: Serve with baguette, for example.
Tip: Stock up on high-quality spices – it pays off!