Wash the potatoes thoroughly and cook covered in boiling water for about 15 minutes. Clean, wash and cut the cauliflower into florets. Blanch the cauliflower florets in boiling salted water for approx. 5 minutes, remove and drain well in a sieve
Heat the fat in a saucepan. Dust with flour and sauté briefly. Add stock and milk, bring to the boil and simmer for 5-7 minutes. Wash the dill, shake dry. Pluck flags from the stalks and chop finely, except for a little to garnish. Stir the chopped dill into the béchamel sauce. Season to taste with salt, pepper and lemon juice
Drain the potatoes, rinse and peel. Cut potatoes into large cubes. Heat 2 tablespoons of oil in a large frying pan. Fry the potato cubes for about 4 minutes while turning. Season with salt
Wash the salmon, dab dry and cut into pieces of approx. 4 x 4 cm. Heat 1 tablespoon of oil in a large, coated frying pan. Fry the salmon in it on both sides for about 2 minutes. Take out, season with salt and pepper
Grease an ovenproof casserole dish (20 x 30 cm). Put cauliflower, potatoes and salmon into the dish. Pour sauce over it and sprinkle with cheese. Cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 15-20 minutes. Take out and garnish with dill