First sprinkle the apple and avocado slices with lemon (or lime if you prefer) juice, to prevent browning.
Then make a vinaigrette, by combining well the vinegar, tomato purée, olive oil, salt, pepper and sugar. Adjust the seasonings to taste.
Add the chopped tomato and onion, and mix thoroughly.
On each plate, place a "sun"-pattern of Avocado slices, thinner ends pointing outwards.
On top of these, overlapping the gaps, place another "sun"-pattern of apple slices.
Divide the crayfish equally over the 4 plates, by piling them in the middle of the pattern.
Spoon the vinaigrette evenly over the crayfish piles.
Finish by giving dill branches a "hair-cut" over the plates, and/or strewing chopped chives about. I like laying 2 long unchopped chives diagonally across the plate. Dot some lemon or lime slices or wedges about, if you like.