Step 2
Heat butter, heavy cream and milk for 1 1/2 minutes. Slowly stream heated butter/cream mixture into potatoes while beating on LOW until combined. Beat in Parmesan, sour cream, chives, salt, pepper and garlic powder on MEDIUM just until combined. Stop beating at this point for fluffy potatoes. For creamier, more dense potatoes, continue to beat just a little longer but be aware not to overbeat. Taste and season with additional salt and pepper if desired.