Cook the potatoes in boiling water for about 20 minutes. Quench cold, peel and cut into slices. Meanwhile wash tomatoes and lemon and cut into slices. Wash the fish and pat dry. Season with salt and sprinkle with lemon juice. Turn in flour. Heat the lard in a large pan.
Fry the lemon sole for 5-7 minutes on each side. In the meantime, fry the potatoes in hot oil for about 5 minutes, turning them over. Sauté the tomatoes and lemon slices briefly and season with salt and pepper. Pluck off basil leaves and fold in. Serve lemon sole and roasted vegetables with caviar. Serve garnished with fresh herbs and lemon wheel