Place the potatoes into a pot and cover with salted water; bring to a boil, reduce heat to medium-low, cover, and simmer until tender, about 20 minutes. Drain and allow to steam dry for a minute or two. Cut the meat from the turkey legs, discarding the bones and tendons. Chop the turkey meat and set aside.

Heat the butter in a soup pot over medium heat; cook the onion in the butter until translucent, about 8 minutes. Sprinkle the flour over the butter and onion; stir constantly until the butter and flour form a paste. Allow the paste to fry for about 1 minute. Whisk in the chicken broth, potatoes, turkey meat, and corn; stir until the mixture comes to a low boil and thickens, about 5 minutes. With a potato masher, slightly mash the potatoes and vegetables until the potatoes look rounded off. Pour in the cream, bring soup back to a simmer, and allow to cook without boiling for 5 minutes, stirring constantly. Season to taste with salt and black pepper.