From Vegetarian Cooking For Everyone by Deborah Madison
1 small russet potato
2 lbs turnips and/or rutabagas peeled
2 medium leeks
1 garlic clove, thinly sliced
salt and freshly ground pepper
2 Tbls or more cream, buttermilk, or milk
2 Tbls butter
2 tsp chopped thyme
Chop the potato and turnips the same size. If using rutabagas, chop them about half the size of the potato. Put the vegetables, leeks, and garlic in a pot with cold water just to cover, add 1/2 tsp salt, and simmer, partially covered, until tender, 15 to 20 minutes. Drain, reserving the liquid.
Mash the vegatables with a fork for a rough-textured puree or pass them through a food mill. Add 2 TBLS or more cream or reserved broth to thin the puree. Stir in the butter and thyme and season with salt pepper to taste.
Variations: Stir 1 cup Gruyere cheese into the puree. Or simmer the vegetables in milk instead of water.