For the pike-perch fillet, finely grate the cabbage and cut the kohlrabi into cubes of about 1/2 cm. Melt butter in a pot and sauté cabbage and kohlrabi. Deglaze with white wine and add vegetable stock.
Season with salt, pepper and nutmeg and simmer for about 5 minutes. Stir in sour cream and boil down vegetables until creamy. Finally, season with caraway seeds and lemon juice and keep warm.
Cut the carefully boned pike-perch fillets into pieces. Season with salt and pepper and rub well with wasabi paste.
Heat olive oil in a frying pan and sear the fillets with the skin side down. Repeatedly baste with frying residue. Add thyme sprig and turn fillets.
Arrange the cabbage and beetroot vegetables on warmed plates. Place the pike-perch fillets on the vegetables and sprinkle with fresh parsley.