Clean and wash the spinach. Blanch in boiling water, pour into a sieve, quench cold and drain. Peel shallots and garlic and dice finely. Wash sage, dab dry, pluck leaves from the stalks and cut finely.
Roughly chop the spinach. Fry 2/3 of the shallots in 2 tablespoons of hot olive oil. Add the garlic and spinach and fry. Season to taste with salt, pepper and nutmeg and set aside. Fry the rest of the shallots in 2 tablespoons of hot oil.
Deglaze with cream and remove from heat. Stir in sage and half of the parmesan. Season to taste with salt and pepper. Grease an ovenproof dish. Place the lasagne sheets and spinach alternately in the mould and pour some sauce over each.
Finish with a layer of lasagne plates. Spread the rest of the sauce on top. Sprinkle with the rest of the cheese. Bake spinach lasagne in a preheated oven (electric: 175 °C/ gas: level 2) for approx. 40 minutes. Serve garnished with sage as desired.