Directions

1. In a small saucepan, saute garlic in olive oil until golden. Stir in sage, and remove pan from heat. Let mixture stand 15 minutes, and drain the oil through a fine sieve into a small bowl, discarding solids.
   

2. While the olive oil and sage mixture stands, in a small skillet, heat 1/8 inch oil over moderately high heat until hot but not smoking, and fry sage leaves, 1 at a time, about 3 seconds each, until crisp. Using a slotted spoon, transfer each sage leaf to paper towels to drain. Sprinkle sage leaves with coarse sea salt.
   

3. Preheat oven to 350°F.
   

4. Peel potatoes and quarter. In a large saucepan, cover potatoes by 1 inch with salted cold water. Bring water to a boil, then reduce to a simmer; cook until tender, about 20 minutes. Reserve about 1/3 cup cooking liquid and drain potatoes.
   

5. While potatoes are still warm, force them through a potato ricer or using medium disk of a food mill, smoosh cooked potatoes into a bowl. Beat in yogurt, butter, garlic-sage seasoned oil, and enough reserved potato-cooking liquid for the potatoes to reach desired consistency. Add salt and pepper to taste.
   

6. Transfer potatoes to an ovenproof serving dish. Mashed potatoes may be made up to 1 day ahead and chilled, covered.
   

7. Heat potatoes in oven until heated through and top with fried sage leaves.