Place the scampi in boiling salted water and simmer at low heat for about 5 minutes. Remove the scampi from the shell, except for the tail. Then remove the intestines. Season scampi with salt and pepper and sprinkle with lemon juice and, if desired, Worcester sauce.
Allow to soak briefly. Sort the spinach and wash thoroughly several times. Peel onion and garlic. Chop the onion finely and press the garlic through a garlic press. Heat the fat in a saucepan, sauté the onion and garlic and add the dripping wet spinach.
Cover and allow to collapse over medium heat. Then steam for 5 minutes, stirring occasionally. Season spinach with salt, pepper and nutmeg. Cut mozzarella into slices and halve them again.
Arrange the spinach in 4 gratin dishes and arrange 3 scampi on each. Cover with morzzarella and bake under the preheated grill for 3-5 minutes. Garnish with lemon and dill.