How to Make It
Combine the first 4 ingredients in a Dutch oven; cover with water, and bring to a boil. Cover, reduce heat, and simmer for 20 minutes or until tender. Drain, reserving 1 cup cooking liquid. Discard bay leaf.
Combine potato mixture, reserved cooking liquid, salt, and pepper in a bowl; beat at medium speed of a mixer until smooth. Drizzle oil over potatoes.