Peel the avocado and cut it in half crosswise. Reserve one half and slice the rest thinly.
Cut a slice from the lemon and chop the rest into very small pieces.
Place a layer of mayonnaise, a few slices of avocado, prawns and small pieces of lemon on thefirst Sigdal cracker. Add salt and pepper to taste.
Repeat the same operation with the second cracker and then superimpose it on the first.
Garnish the avocado half with the remaining prawns and dill.
Place it on the last cracker which has been garnished with the lemon slice.