Soften the beet with the bay leaf in salted water over medium heat for 1 hour with the lid closed.
In the meantime, for the soup, rinse and clean the leeks, cut the white and light green into 2 cm slices. Peel the potatoes and cut them into pieces of 2 cm.
Heat oil and sauté leek over medium heat for 1-2 minutes without coloring. Add potatoes, stock and whipped cream. Cover and cook over medium heat for 20 minutes. Add wasabi and blend finely with a hand blender. Season with salt. Keep warm.
Peel beet and cut into 2-3 mm wide strips. Cut turbot into 3-4 cm pieces and turn in flour to the other side, tap off excess flour.
Heat butter and fry turbot in it over medium heat for 1 minute on both sides. Season lightly with salt, season with pepper and drain on paper towels. Evenly distribute the beet and fish over the soup.