3 large parsnips (about 1 lb.), peeled and cut into 1-inch cubes
3 lb. russet or Yukon Gold potatoes, peeled and cut into cubes that are a little larger than the parsnips
4 large cloves garlic, crushed and peeled
1 cup whole milk, half-and-half, or heavy cream
2 tbsp. butter
White pepper or finely ground black pepper
¼ tsp. freshly grated nutmeg
Chopped chives or parsley, for serving
In a large pot, cover the parsnips, potatoes, and garlic with a couple of inches of cold water. Bring to a boil over high, season generously with salt , and cook until tender, 20 to 25 minutes.
Meanwhile, in a small pan, heat the milk and butter over low until the milk is warm and the butter melts.
Drain the vegetables. For a smooth mash, pass the vegetables through a food mill. For a more rustic mash, transfer the vegetables to a large bowl and smash with a potato masher. Stir in the milk mixture; season with pepper and the nutmeg.
Transfer to a serving bowl and top with the chives or parsley.