Finely puree all ingredients with a food processor. Let rest at room temperature.
Bring the stock to the boil, gradually add the polenta and cook for about 20-30 minutes, stirring constantly. The polenta mass should still be very thick.
Spread the polenta mixture well on a greased oven tray, let it get lukewarm, spread the pesto mixture evenly over it.
Roll up the polenta plate slightly from one side. Lift the tray from the same side so that the plate can roll up almost by itself and twist onto a plate.
Let it set in the refrigerator for about an hour.
Cut the polenta into slices, place on edge in a baking dish and open up
Bake for about 200 degrees for 20 minutes. possibly sprinkle some parmesan on top.