Halve melons, remove seeds. Use a ball cutter to cut out as many balls as possible from the flesh. Take out the rest of the flesh with a spoon and use it for other purposes. Drain the crabs. Peel and finely dice the shallot. Wash the dill, dab dry and chop finely. Mix vinegar, honey, shallot, dill, peppercorns, some salt and pepper.
Whip the oil into it. Mix vinaigrette with prawns and melon balls. Wash the rocket, dab dry, sort and cut into strips, except for a few nice leaves. Add to the crab and melon mixture. Spread the cocktail into the melon halves and garnish with the rocket leaves and dill flowers. Serve with fresh baguette