Prepare balsamic dressing and set aside until ready to use.
Separate leaves from Romaine, cut larger leaves in half down the center and transfer to a mixing bowl.
Cut cooked beets into halves or quarters, depending on size.
Wash and slice watermelon radish, if large, cut in half.
Transfer lettuce to individual serving plates, dot with cooked beets and tuck the radishes in between the leaves.
Sprinkle with crumbled feta cheese.
Pass dressing separately.