Peel and wash the potatoes and cook them in boiling salted water for about 20 minutes. Cucumbers wash, clean, cut in half lengthwise, remove seeds. Cut the cucumbers into slices. Peel and finely dice onion.
Wash the dill and thyme and shake dry. Remove leaves or flags from the stalks and chop finely, except for a little to garnish. Peel garlic and chop finely. Wash lemon hot, grate dry, halve fruit and squeeze juice.
Whisk 4 tablespoons of oil, honey, 4 tablespoons of lemon juice, lemon zest, except for something to sprinkle, dill and thyme, except for something to sprinkle. Season with salt and pepper. Wash the fish, dab dry. Place on an oiled baking tray and sprinkle with prepared marinade.
Cook the fish in the preheated oven (electric cooker: 200 °C/ circulating air: 175 °C/ gas: see manufacturer) for approx. 20 minutes. Meanwhile heat 2 tbsp. oil and sauté onion for approx. 10 minutes until transparent. After approx. 5 minutes add cucumbers.
Season with salt and pepper and add 100 ml water. Stir in crème fraiche. Carefully fold in the potatoes and keep warm in a closed pot.
Sprinkle the finished fish with remaining herbs and lemon peel. Arrange fish and vegetables and garnish with herbs.