Melt 30 g fat, stir in flour and sweat briefly. Add milk and cream bit by bit while stirring. Season sauce with horseradish, salt and pepper and simmer for 10 minutes at low heat while stirring.
Rinse fish cold and pat dry. Boil up about 1 litre of water with lemon juice and salt. Add the salmon fillet and stew at low heat for about 10 minutes. In the meantime, clean broccoli, cut into florets and wash.
Cover and cook in 3/8 litres of boiling salted water for 8-10 minutes. Remove fish from the cooking water and drain well. Place in an ovenproof dish, pour sauce over it and bake in a preheated oven (electric cooker: 200 °C/ gas:
Clean, wash and dry the tomato. Cut into quarters and remove seeds. Cut the flesh into small cubes. Peel and finely dice onion. Sauté in the remaining fat. Drain broccoli and let it drain.
Add broccoli and tomatoes to the onion and toss briefly in the fat. Serve the vegetables on the fish platter or separately. Garnish fish with slices of lime or lemon and dill.