Blanched tuna cubes are a beautiful way to present your tuna and provide an alternative to serving the fish completely raw. The very quick blanching in Dashi gives the tuna great flavor, but it retains that very fresh taste and bite. You can also use this method for creating unique sashimi pieces. This is a definite must-try for your sushi repertoire!
Make a large batch of Dashi Stock (approximately 2 litres). If you don’t know how to make Dashi stock, watch this video How to Make Dashi Stock.
Pour half of your Dashi stock into a medium bowl and put into the freezer, you want it to be very cold but not frozen so take it out before it freezes completely.
Heat the other half of your Dashi stock to a soft boil.
While the Dashi is heating up, cut the tuna into a long thin rectangle that is the length of your block of tuna and 2.5cm (1 inch) square at the end.
Take your cold Dashi stock out of the freezer, and place the bowl next to the stove top on the counter.
With the tongs, gently place the tuna into the boiling Dashi and blanche for 2-3 seconds. Remove from the boiling stock and place immediately into the cold Dashi stock to stop the cooking.
Gently lay your tuna on the chopping board. Slice it into cubes using a very sharp knife. Make one clean slice per cut, do not saw through the tuna.
Place the tuna pieces onto a plate by scattering the pieces around so that you can see all of the edges and angles of the tuna. Add a few pieces of lettuce around the cubes to garnish, but don’t go overboard as less is more. You could also add a few carrot butterflies to garnish. Click here for the tutorial on how to make carrot butterflies.
What should you do with all of that leftover Dashi stock? I suggest ladling your leftover stock into an ice cube tray and freezing it. When you need a quick liquid flavour injection for anything you are cooking just pop out a cube or two and add it to your food instead of water. You can also do this with leftover vegetable, chicken or beef stock, and add it to soups, stews, and many other dishes for a depth and intensity of flavour that you simply cannot get with plain water.