1Place a steamer insert into a saucepan and fill with water to just below the bottom of the steamer. Bring water to a boil. Add beets, cover, and steam until tender, about 10 minutes. Let cool; trim, peel, and dice beets. Transfer into a bowl.
2Place eggs, apple, walnuts, mayonnaise, parsley, and salt into bowl with beets; toss to combine. Spread salad onto bread slices to serve.