Dice the tuna into 1cm cubes. Remove the skin and pit from the avocado, cut into bite-sized pieces, and coat with lemon juice.

Crack the eggs into a bowl and whisk. Add the egg mixture seasoning and mix well.

Heat salad oil in a tamagoyaki pan over medium heat. Pour in the egg mixture and cook until semi-set. Fold and cook further, then cut into 1cm cubes.

Mix the sushi vinegar ingredients in a bowl.

Combine the cooked rice with the sushi vinegar in a separate bowl and let cool to room temperature.