Bring the milk to the boil and stir in the polenta.
Cook for about 20-30 minutes at medium heat or in the oven and
stir regularly.
Season with butter, olive oil, finely grated Parmesan, salt and
pepper and finely puree with a hand-held blender. The mixture should
have a liquid consistency; add some milk or vegetable stock if
necessary.
Pass the mixture through a sieve directly into a 0.5 l
Whipper.
Screw on 1 N2O Charger and shake vigorously.
Keep the Whipper warm at a constant temperature of max. 75 °C in
a bain-marie or water bath.