For the ginger-soy dipping sauce: Combine the soy sauce, vinegar, chile garlic sauce, garlic, scallions and ginger in a small bowl. Stir well to combine and set aside.
For the spicy tuna: Mix the tuna with the mayo and chile garlic sauce in a medium bowl. Lightly toss to coat and set aside.
For the sushi roll: Prepare a bamboo sushi rolling mat by wrapping it completely in a tight layer of plastic wrap. Additionally, fill a small bowl with water and the rice wine vinegar and set aside.
Fold a sheet of nori about an inch up and remove the bottom piece. Briefly toast over an open flame until pliable, about 10 seconds.
Put the toasted nori sheet shiny-side down on the wrapped bamboo mat. Gently press and spread some of the rice on the nori sheet, leaving about 1 inch exposed on top. Dip your fingers in the water/vinegar bowl if the rice is sticking to your hands.
Starting about 1/2 inch up from the bottom of the nori, spread a very small amount of wasabi paste along the length of the sheet. Spoon an even layer of the spicy tuna over the wasabi and place some of the cucumber strips on the sides of the spicy tuna. Add 3 to 4 pieces avocado in a single layer. Roll the nori up over the fillings and tuck under to enclose entirely. Gently press the bamboo mat and continue rolling to tighten. Remove the bamboo mat and trim the ends of the roll.
With a clean knife, cut the sushi roll in half. Line up the halves and cut through both rolls to make 6 even pieces. Repeat this process with the remaining ingredients to make the second roll. Serve the rolls with a dollop of wasabi paste and small bowls of the dipping sauce.