Wash the orange with hot water, pat dry and rub the peel off. Squeeze the orange and lemon. Mix the orange peel, orange juice, lemon juice, linseed oil, salt, pepper and mustard into a marinade.

Wash the potatoes and cook in salted water for about 20 minutes. Wash, peel and quarter the apple and remove the core. Dice the apple. Drain the beetroot. Peel the potatoes and cut them into slices, mix with the apple cubes, beetroot slices and the marinade. Chop and fold in the dill.

Clean the cod fillet, sour and salt. Melt the butter in a pan. Fry the fish in it for 3 minutes per side. Serve with the beetroot and potato salad. Bon Appetit!