Put the salmon in a heat-resistant container. Pour on the sake and cover with plastic wrap. Microwave for 3-4 minutes.
Remove the skin and bones from the salmon from Step 1 and break apart the flesh.
Put Step 2, including the juices, into a frying pan. Add the mirin and sugar and cook until the liquid evaporates. Optionally sprinkle with white sesame seeds.
Story Behind this Recipe
I've been making this recipe for a very long time.
You can optionally add salt. These can keep in the fridge for 3-4 days. They also taste great if you grill them and then make the flakes. In that case, add the sake after grilling. The cooking time varies depending on your microwave, so keep your eye on them and adjust accordingly.