Soak the sultanas in lukewarm water. Clean and wash the leeks and cut them into rings. Heat 1 tablespoon of oil. Steam the leek for about 5 minutes. Roughly chop the capers. Squeeze sultanas.
Add capers and sultanas to the leek after about 3 minutes. Add 100 ml water, bring to the boil and simmer for about 5 minutes. Season with salt and pepper. Meanwhile wash the fish, pat dry and season with salt.
Heat 2 tablespoons of oil. Fry the fish fillets in it in portions on each side for about 2 minutes. Sprinkle with lemon juice. Arrange leek vegetables and fish.