1. Prepare sushi rice base.
2. In a small bowl, add chopped tuna, and mayonnaise. Gently mix to combine.
3. Lay lettuce, tuna mixture, and cucumber on rice base.
4. Grab the bamboo mat, lift it over and roll as shown in the video. Squeeze firmly but gently.
5. Once done, open and remove bamboo mat.
5. Place sushi rolls on the cutting board, and with a sharp knife cut it into slices. Wipe knife every time with a towel dipped in water and rice vinegar mixture.
6. Serve tuna fish roll with wasabi and ginger.