Rinse the fillets, dab dry and cut in half. Fry in hot butter until golden brown all around. Peel onion, dice finely and fry briefly. Season with salt and pepper
Wash herbs, chop. Add to meat and fry briefly. Squeeze lemons. Add juice and about 8 tbsp. water. Cover and stew for 15-20 minutes. Season to taste with salt, pepper and sugar