Sauté the shallots in the hot butter in a saucepan and let the sugar caramelize. Add red and port wine, vinegar and rosemary, season with salt and pepper and let it simmer for about 1 1/2 hours over low heat.
Chop the pepper berries and mustard seeds, mix with the chili powder, sea salt, curry and black pepper.
Press the fish fillets with the skin side firmly into the breading. Place skin side down in a cold, coated pan and slowly fry on this side until crispy. Then let the fish steep in the preheated oven at 80 ° C for about 10 minutes.