Preheat the Oven: Preheat your oven to 400°F (200°C) and lightly grease a muffin tin with non-stick spray or butter.
Mix the Ingredients: In a large mixing bowl, combine the mashed potatoes, shredded cheese, eggs, sour cream, and herbs. Season with salt and pepper. Mix until smooth and evenly combined.
Spoon into Muffin Tin: Using a spoon or scoop, divide the mixture evenly among the muffin tin cups. Fill each about three-quarters full.
Optional Topping: Sprinkle the tops with a little grated Parmesan for a crispy golden crust.
Bake: Place the muffin tin in the preheated oven and bake for 20–25 minutes, or until the tops are golden brown and the puffs are set.
Cool Slightly and Serve: Allow the puffs to cool for a few minutes before removing them from the muffin tin. Serve warm as a side dish or snack.