Clean, wash and chop the celery and peppers. Peel and finely chop the onion. Wash the fish, sprinkle with lemon juice and season with salt and pepper. Heat 10 g fat in a pan and fry the onion in it.
Deglaze with broth and stew the fish in it at low heat for about 15 minutes. In the meantime, heat the remaining fat and cook the vegetables in it for about 10 minutes. Put the sauce in a pot and heat it up at medium heat.
Wash the chives, dab dry and cut into small rolls. Add chives and capers to the sauce and stir in. Arrange vegetables and fish on plates. Sprinkle fish with coloured pepper and pour sauce over it.
Serve garnished as desired with a slice of lemon, chives and celery leaves. Boiled potatoes taste good with it.