In a saucepan combine cream, cornflour and condensed milk. Bring to a simmer, stirring constantly. Remove from heat and pour into a non-stick baking pan. Cover well with plastic and chill 2 hours.
Make the batter: combine flour, polenta, baking powder, salt and enough beer to make a thick batter.
Dice up the set milk mixture into cubes, dip in the batter and deep fry until golden brown.