Wash the char fillets and pat dry. Mix herbs and spices, salt and sugar and cover fillets with it (marinate for about 12 hours).
Boil asparagus until firm to the bite (up to 8 minutes depending on thickness) and rinse with cold water.
Sauté diced vegetables in olive oil, add mushrooms and deglaze with wine. Add the tomato stock and reduce.
When the vegetables are firm to the bite, add the oil and season with lemon vinegar, salt and pepper.
Remove the char fillets from the marinade, cut into thin strips, arrange with asparagus and vegetables.