Cook the rice

1. Place the rice in a large bowl cover it with water and leave to soak for 10 minutes. Then rinse the rice until the water is clear.
2. Place the rice in a saucepan and cover with water.
3. With the lid on boil on a high heat for 5 minutes then lower the heat and simmer for 10 minutes until the water has been absorbed. (Notes 1 & 2). You can make the eel sauce and sriracha mayo while the rice cooks.
4. Leave the rice with the lid on and mix the rice vinegar, salt and sugar in a small jug or bowl.
5. Transfer the rice to a large shallow dish or tray, pour on the rice vinegar mixture and fold in gently with a large spoon until evenly distributed. 
6. Leave the rice to cool

Eel Sauce

1. Add the eel sauce ingredients to a small pan, mix and bring to boil for 10 minutes. Remove from the heat and set aside. The sauce will thicken as it cools.

Sriracha Mayo

1. Mix the sriracha mayo ingredients in a small bowl and set aside.

Vinegar water for hand dipping

1. Mix the water and rice vinegar in a medium bowl that is large enough to dip your hands into and set aside.

Preparing the sushi

1. Take a piece of nori and place on the rolling mat with the rough side up.
2. Dip your hands into the water and rice vinegar tezu and spread an even layer of rice onto the nori sheet ensuring it reaches the ends and corners.
3. Flip the sheet over and place the fish, avocado and cucumber at the bottom of the nori.
4. Roll tightly until the bottom edge of the rice touches the nori sheet.
5. Then place the bamboo mat on top and tightly squeeze the roll.
6. Repeat steps 1 to 5 to make 3 more rolls.
7. Drizzle each roll in eel sauce then drizzle with sriracha mayo.
8. Top with an even layer of crispy fried onions.
9. Wet the blade of a sharp knife and cut each roll into eight even slices by cutting the roll in half, then cutting each section in half and half again.
10. Serve immediately with soy sauce, wasabi and sushi ginger or refrigerate to enjoy later.