01 - Preheat oven to 400°F. Lightly grease a baking sheet or line with parchment paper.
02 - If using fresh potatoes, peel and boil until tender. Drain thoroughly, then mash with 2 tablespoons butter and milk until smooth. Season with salt and pepper. Cool slightly before proceeding.
03 - In a large mixing bowl, combine the prepared mashed potatoes with shredded cheddar, Parmesan, beaten eggs, chopped chives, smoked paprika, and flour. Mix thoroughly until all ingredients are evenly incorporated and the mixture is smooth.
04 - Using a spoon or small ice cream scoop, portion approximately 12 evenly-sized dollops of the potato mixture onto the prepared baking sheet, spacing them about 2 inches apart to allow for expansion.
05 - Brush the tops of each puff with melted butter to promote even browning and a golden finish.
06 - Bake for 25 to 30 minutes until the puffs are golden brown on top, puffed, and set in the center. The tops should feel firm to the touch.
07 - Remove from oven and let cool on the baking sheet for 3 to 5 minutes to set. Serve warm, optionally topped with a dollop of sour cream.