A tasty twist on simple mashed potatoes - the sweet potato and zesty yogourt give this dish the upper hand on your festive holiday table.<br /><br />Ingredients<br />4 unpeeled garlic cloves<br />½ teaspoon extra-virgin olive oil<br />2 medium sweet potatoes (about 1 pound total)<br />2 medium russet potatoes (about 1 pound total)<br />1 tablespoon unsalted butter<br />2 tablespoons coarsely chopped fresh flat-leaf parsley, plus for garnish<br />1 tablespoon finely chopped fresh sage<br />1¾ teaspoons coarse salt<br />Pinch of freshly ground pepper<br />½ cup plain yogurt or sour cream<br /><br />Method:<br />Preheat oven to 400ºF, with racks in centre and lower thirds. Put garlic on a piece of aluminum foil; drizzle with oil. Fold to form a packet. Place garlic packet and the potatoes on centre rack; with a baking sheet on lower rack to catch any drips.<br /><br />Bake, until the potatoes are very tender when pierced with the tip of a knife, about 60 minutes. Remove from oven and let cool slightly, about 5 minutes.<br /><br />Skin the potatoes and pass through a ricer into a medium bowl. Squeeze garlic from skins into bowl with potatoes. Stir in butter, parsley, sage, salt, and pepper. Stir in yogurt, and serve.
