Drain the tuna and stir into the cream cheese. Season to taste with salt and pepper.
Put a layer of creamed spinach in a baking dish. Put a layer of lasagna on top and then spread the tuna cream. Then put the lasagne sheets on top again. Keep doing this until the baking dish is full. Now pour the tomato sauce over it and sprinkle with cheese.
Bake in the preheated oven on the middle rack at 180 ° C for approx. 50 minutes.