Make sauce by lightly sauteing mushrooms, ham, onions, and garlic in butter. When onion is tender, add flour, salt, and pepper. Stir, then add beef broth and wine. Cover and simmer for 45 minutes. While sauce is simmering, prepare breasts by dipping then into a mixture of flour, salt, and paprika. Melt butter in a shallow baking pan in a 400-degree oven. Remove baking pan and coat floured duck breasts in melted butter. Arrange breasts in a single layer in pan and bake at 400 degrees for 30 minutes. Turn. Pour wine sauce over breasts. Cover pan with foil and cook breasts until tender (another 45 minutes).