Prepare the cucumber. Peel, cut off the ends, slice into quarters lengthwise and the cut-out the seed core. Keep aside.
¼ Cucumber
Slice the tuna into about ¾ inch or 2 cm thick sticks. Keep aside.
1.75 Ounces Raw Tuna
Keep the cooked and seasoned sushi rice ready (follow our handai sushi rice preparation). It should be room temperature.
1 Cup Sushi Rice
Place your sushi mat on a clean working surface and keep a nori seaweed sheet (shiny side down) on the sushi mat, but align it to the bottom edge so that you can easily roll it in afterward.
1 Nori Seaweed
Spread the cooked and seasoned sushi rice over the nori sheet but keep a 1 inch (2.5 centimeters) border at the top only. Stick the rice kernels on the sheet and make it even. The rice shouldn't fall off the nori seaweed.
1 Cup Sushi Rice
Place the tuna sticks horizontally, about 2 inches (ca. 5 centimeters) from the bottom edge, across the rice. Adjust the tuna pieces and cut one small to make them fit next to each other in a line.
1.75 Ounces Raw Tuna
Arrange the elongated cucumber quarter over the tuna and cut another piece of cucumber to fill up your sushi roll. The cucumber pieces should properly fit next to each other.
¼ Cucumber
Gently lift the mat from the bottom edge and gently roll it over the filling, using your fingers to tuck and compress the roll into a tight cylinder. Continue rolling forward, and keep gentle even pressure to shape the roll into a tight sushi roll.
Place your tuna cucumber roll on a cutting board and slice the sushi roll into 8 clean slices.
Serve up at room temperature or cooled.
Notes
Sushi Rice is cooked and seasoned rice. Prepare Handai sushi rice at home and keep it ready to make this sushi rice. You can keep cooked seasoned Japanese sushi rice in the fridge covered in a damp clean clothe so that it doesn't dry out.The tuna needs to be raw sashimi grade fresh tuna (AAA quality).Adjust the quantity of tuna and cucumber strips as per the size of each strip, so that they fit into the sushi roll. Therefore, the weight of the cucumber and tuna in this recipe may vary, and the measurements are merely estimates.