Combine the beets, oil, vinegar, and mustard. Season with 1/2 teaspoon salt and 1/4 teaspoon pepper.
Divide the beets and endive among 4 plates. Top with the parsley, walnuts, and cheese.
Tip: Versatile, delicious cooked beets are available in many supermarkets in Cryovac packages. Look for them in the produce section.