Set your oven to 400°F (200°C) and lightly grease a muffin tin.
In a bowl, whisk together the beaten eggs and sour cream until smooth.
Stir in the shredded cheese, Parmesan, chopped chives, and a pinch of salt into the egg mixture.
Carefully fold the mashed potatoes into the combined mixture until everything is evenly mixed.
Spoon the potato mixture into each muffin cup, filling them to the brim.
Bake for 20 to 25 minutes until the tops turn golden and the puffs rise beautifully.
Let the puffs cool for a few minutes before removing them from the tin.
Serve as a delightful side or snack that brings cheesy, crispy joy to any meal.