Peel and finely chop the onion. Clean and wash the greens. Cut carrots into slices, celery into cubes and leek into pieces. Heat fat in a pot, fry vegetables in it, add rice and fry briefly.
Deglaze with the stock and bring to the boil. Leave to swell over low heat for about 20 minutes. Wash the fish, pat dry and grill in a grill pan or under the hot grill of the oven from both sides for 3 minutes, season with salt and pepper.
Season the risotto with salt and pepper as well and arrange on plates with the cod chops. Garnish with lemon and dill.