Wash the zucchini and cut in half lengthways. Carefully scrape out the inside and set aside. Place the zucchini halves in a lightly oiled baking dish.
Dice the shallots and fry them in the butter until translucent. Dice the zucchini pulp and fry briefly. Add the crème fraîche and crayfish tails and simmer until the liquid is reduced. Mix in the dill and season with salt and pepper.
Pour the mixture into the zucchini halves and sprinkle everything with parmesan. Bake at 200 ° C for about 25 minutes.