01 - Preheat oven to 400°F. Lightly grease a baking sheet or line with parchment paper.
02 - If not using leftovers, peel and boil potatoes until tender. Mash with butter, milk, salt, and pepper until smooth. Allow to cool slightly.
03 - In a large bowl, combine mashed potatoes, cheddar, Parmesan, eggs, chives, smoked paprika, and flour. Mix until smooth and thoroughly incorporated.
04 - Use a spoon or small ice cream scoop to form 12 equal dollops of mixture onto the prepared baking sheet.
05 - Brush tops of each puff with melted butter for extra golden color.
06 - Bake for 25-30 minutes until puffs are golden brown and set throughout.
07 - Let cool for a few minutes before serving. Serve warm with sour cream if desired.