Bring 1/2 litre of salt water to the boil. Take the pot off the stove. Add milk and fat. Stir in puree flakes. Let it swell for about 1 minute and stir again. Season mashed potatoes with salt, pepper and nutmeg.
Boil the vegetables and 1/4 litre of salted water in a saucepan over a low heat for about 5 minutes. Drain the vegetables on a sieve. Cut Cabanossi into slices. Grate cheese roughly. Spread the mashed potatoes in a greased casserole dish.
Mix the vegetables and cabanossi and spread on top. Sprinkle cheese over it and bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 15 minutes.