Melt the butter in a wide saucepan. Wash and add the spinach, steam for 2-3 minutes and season to taste with salt, pepper and nutmeg. Drain the spinach. Peel onions and cut into slices. Roll out the pizza dough and place it on a baking tray lined with baking paper. Spread tomato sauce on the dough, then cover with onions and spinach.
Sprinkle cheese on top. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 15-20 minutes until golden brown. In the meantime, prick eggs at the blunt end and cook in boiling water for 9-10 minutes. Peel and slice the eggs. Take the pizza out of the oven and cover with slices of egg