Peel and wash beetroot (use disposable gloves if necessary) and sweet potatoes and cut or slice them very thinly. Place 6-7 slices overlapping in a row and roll up. Fix the rolls at even intervals with 2 wooden skewers each. Halve the rolls. Loosen up the flowers with a finger or the tip of a knife. Heat oil and deep-fry the "blossoms" until golden brown. Take out the roses and season with salt