1. Place potatoes, turnips, garlic and 8 sage leaves in a medium saucepan and cover with water. Bring to a boil. Reduce the heat to medium-low, cover, and simmer until the vegetables are fork-tender, 12 to 15 minutes. Drain. Return the vegetables to the pan and keep covered.
2. Heat butter in a small skillet over medium-high heat. As it melts and turns lightly brown, add the olive oil and strips of sage and allow them to crackle and flavor the butter, about 1 minute.
3. Pour the sage and olive oil over the vegetables and smash with a potato masher. Stir in salt and pepper and serve.
Original recipe and photo from Eating Well Magazine, November-December 2010. I substitued olive oil for butter and reduced the amount of sage. We found 30 leaves of sage to be too strong flavored.