Preheat and Prepare: Preheat your oven to 200°C (180°C fan). Generously grease a 12-hole standard muffin tin with butter or a neutral oil spray. This is a crucial step to prevent sticking, so don't be shy!

Combine Wet Ingredients: In a large mixing bowl, add your cold mashed potatoes. Break them up a little with a fork. Add the lightly beaten eggs and the soured cream, and mix gently until just combined.

Add Dry Ingredients and Cheese: To the bowl, add the plain flour, about two-thirds of the grated cheddar (saving the rest for the topping), the chopped chives, garlic powder, onion powder, salt, and pepper.

Gently Fold Together: Using a spatula, gently fold all the ingredients together until they are just incorporated. Be careful not to overmix, as this can make the potato tough and gummy. The mixture will be thick and a little lumpy.

Portion the Mixture: Using an ice cream scoop or two large spoons, divide the potato mixture evenly among the 12 prepared muffin cups. They should be filled almost to the top. What works best for me is to slightly mound them in the centre.

Top with Cheese: Sprinkle the remaining grated cheddar cheese evenly over the top of each muffin.

Bake Until Golden: Place the muffin tin in the preheated oven and bake for 20-25 minutes. You're looking for them to be puffed up, golden brown, and for the cheese on top to be melted and bubbling.

Cool and Serve: Remove the tin from the oven and let the muffins cool in the tin for at least 5-10 minutes. This helps them set and makes them much easier to remove. Run a thin knife or spatula around the edge of each muffin to loosen, then carefully lift them out. Serve warm.