Heat 4 teaspoons oil in a medium skillet over low heat. Add shallots to pan, and cook for 5 minutes, stirring occasionally. Sprinkle with sugar; cook 20 minutes or until shallots are golden, stirring occasionally.
Place potatoes in a medium saucepan; cover with water. Bring to a boil; cook 8 minutes or until tender. Drain. Place potatoes in a large bowl; beat with a mixer at medium speed until smooth. Add rosemary, salt, and pepper; beat until blended. Spoon into a bowl; top with shallots, and drizzle with remaining 1 1/2 teaspoons oil.
I was skeptical about this recipe because it does not contain any cream or butter, however I was blown away by the flavor and the texture! It has everything you would love about mashed potatoes, with the enhanced flavor of sweet potato, and the fresh rosemary is out of this world! Five-star restaurant quality. I will definitely be making this for dinner guests!