Fry the char fillets in a non-stick pan in little olive oil with finely chopped garlic, salt and pepper.
Cut the rye bread into cubes, gratinate in the oven, chop in the blender and mix with the finely chopped mountain herbs.
Boil the milk for the polenta. Add salt and the cornmeal in small quantities and stir constantly with a whisk until the polenta is cooked and of the desired consistency. Season with salt and allow to cool in a mold. Cut the cooled polenta into cubes.
Rub the fish fillets generously with the bread-herb mixture, place them with the polenta cubes in a fireproof mold and bake in the oven for approx. 4 minutes until everything is slightly crispy.
Arrange char and polenta on 4 plates and decorate with the sage.