In steamer over boiling water, steam rutabaga until nearly tender, about 15 minutes. Add pear and continue to cook for another 5 to 10 minutes, until rutabaga is tender. Remove from heat and drain well.
Puree rutabaga and pear in food processor until smooth. Add yogurt, butter, and seasonings to taste.
Heat in microwave at medium heat until heated through (or in a saucepan).
Variation: For Rutabaga and Apple Puree, use 1 apple in place of the pear.