To make the polenta stuffing, put the quick-cook polenta in a mixing bowl and quickly whisk in the hot chicken stock. Stir in the gorgonzola and spinach.
Stuff the chicken breast with the mixture, pushing the stuffing into the slit.
Heat the olive oil in a frying pan and fry the chicken breast, skin side down, for 5-7 minutes or until crisp and golden. Turn the chicken over and finish cooking on the other side for a further five minutes or until cooked through.