To prepare pesto, combine first 4 ingredients in a blender; process until smooth, scraping sides.
To prepare potatoes, place potato in a saucepan, and cover with water. Bring to a boil. Reduce heat; simmer 15 minutes or until tender.
Drain and return potato to pan. Add cheese and remaining ingredients; mash to desired consistency. Cook potato mixture 2 minutes or until thoroughly heated, stirring constantly. Drizzle each serving with 1 tablespoon pesto.