Prepare a thick polenta, pour it into a pan and let it cool completely.
Meanwhile, fillet the mackerel (unless they are ready canned) and, in a bowl and with a fork, mix the mackerel fillets with the fresh cheese, mustard, lemon juice, wine, l chives and coarsely chopped capers.
Mix everything in order to obtain a cream and season with salt and pepper.
Cut the polenta into slices and roast them for a couple of minutes per side on the grill.
Serve the grilled polenta sprinkled with the mackerel cream and a sprinkling of chopped red pepper.