Combine turnip and onion in a small bowl. Toss with salt and pepper.
Unfold piecrusts, and press out fold lines. Cut out 30 rounds with a 2-inch round cutter.
Place 1 teaspoon turnip mixture on half of each round, and fold the other half over. Press edges together with a fork to seal. Place on an ungreased baking sheet; brush tops with melted butter.
Bake at 375° for 15 to 17 minutes or until edges are lightly browned.
Turnip-Bacon Turnovers: Add 4 to 5 pieces finely chopped, cooked bacon to filling mixture. Proceed as directed.