Step 1

Gather all the ingredients. I also use one 1 ¾ inch (4.5 cm) round cookie cutter.

Step 2

Dice tuna and lightly marinate the tuna with scallion, soy sauce, and sesame oil.

Step 3

Slice the cucumber with a peeler to make long thin strips.

Step 4

Place shiso leaves on a serving platter. Dip a cookie cutter in a bowl of water (so the rice doesn't stick) and place it on top of a shiso leaf. Stuff sushi rice into the cookie cutter halfway and remove the cutter gently. Roll the sushi cylinder with one strip of cucumber slice to measure the circumference of the circle.

Step 5

Make slits at the end of the cucumber slice with a knife as you see below. Now you can interlock the strip around the rice.

Step 6

Fill in the cucumber wrapped sushi with your favorite toppings. For amaebi (sweet shrimp), I place a couple of pieces from the outer edges to the center in the cucumber cup, so it looks like a flower.

Step 7

Slice the sashimi-grade fish perpendicular to the muscle (the white line you see in the fish) and place a few slices in the cucumber cup.

Step 8

Place the tuna mixture in the cucumber cup. Garnish with lemon and kaiware daikon radish sprouts. Serve immediately.

Step 9

I don't recommend keeping sashimi-grade fish and shrimp longer than 24 hours. Keep them refrigerated until serving.