This is how I prepare salmon sashimi at home. While I am using Costco farmed salmon today, I cannot guarantee it is completely safe to eat raw. Consuming raw or undercooked seafood carries a risk of foodborne illness, so always follow proper food safety guidelines and use fish labeled for raw consumption.
Slice the salmon fillet into 8 smaller portions. I did this by slicing once through the middle lengthwise, then cutting each half into 4 smaller portions. The exact size and shape of each portion does not really matter too much.
Combine the salt and sugar in a small bowl.
Apply a thin layer of the salt and sugar around each piece of salmon. Place the salmon pieces on a wire rack and refrigerate for 45 minutes.
Rinse the salmon pieces under cold water then pat dry with paper towels.
Slice the salmon into ¼-inch thick slices. I usually slice them at an angle so they look prettier.