Polenta: Bring to a boil the milk water with the butter or light butter and the onion. Add the corn and cook at low temperature, stirring occasionally, for about 4 minutes, season with salt. Add corn kernels and finish cooking in about 6 min, season.
To serve: pour a third of the polenta into a warmed bowl, make a dent. Mix gorgonzola and half cream, pour in, cover with remaining polenta, spread gorgonzola evenly on top, bring to table on the spot.