Start with the mayonnaise by placing the chopped chives and Dijon mustard in the container of the hand blender.
Break the egg and grate/press the garlic. Pour in the oil.
Carefully insert the hand blender all the way down. Blend on high speed until most of the oil is absorbed. Begin to gently shake the hand blender before lifting it. Blend until the spring onion has entered the mayonnaise. Season with salt and pepper.
Peel and roughly mash the avocado with a little lemon juice, salt and pepper.
Slice the bluefin tuna very thinly, chiffonade it if you have the right knife.
Break several pieces of Sigdal rye and spelt bran crackers into bite-sized pieces.
Place a spoonful of avocado cream on each cracker, followed by a few pieces of tuna chiffonade. Add a touch of chive mayonnaise and decorate with the red cabbage sprouts and alfalfa.