Clean and wash the leek and cut into fine rings. Heat oil and 2 tablespoons of water in a pan. Sprinkle leek, except for a few very fine rings, in it while turning for 2-3 minutes
Season with salt and pepper, take out, drain if necessary and let cool down. Toast bread brown. Season yoghurt with salt, pepper and sugar. Stir in leek. Cut bread into triangles. Halve the maties.
Arrange yoghurt sauce and 2 half matie fillets on plates, sprinkle with pink berries. Add toasted bread.