Wash the potatoes and cook in boiling water for about 20 minutes. Clean, wash and cut the leek into rings. Mix mayonnaise and yoghurt. Drain the peppers, cut into fine cubes and stir into the mayonnaise.
Season to taste with salt, pepper and sugar. Wash and drain the chives, cut into fine rolls and fold into the tartar sauce. Drain the potatoes, rinse, peel and cut into slices. Wash the fish, dab dry and cut into large pieces.
Heat 1 tablespoon of clarified butter in a frying pan. Fry the fish for 3-4 minutes. Season with salt and pepper, remove and keep warm. Put 2 tablespoons of clarified butter in the pan and heat it up.
Fry the potatoes for about 5 minutes, add the leek and fry briefly. Season with salt and pepper. Fold in fish. Arrange the panfish with the pepper remoulade.