Mash the potatoes (while hot). You can use a regular potato masher or potato ricer (the potatoes will be slightly more fluffy). Do not mash them for too long or they will be gummy.
Add all the other ingredients and stir until well combined (but do not stir for too long). It's important to add the other ingredients while the potatoes are still hot.
Season to taste with salt and pepper.
Garnish with more chives and melted butter.
Enjoy!
Notes
Unfortunately, all mashed potato recipes taste best freshly made. But, sometimes there is no time, so what I like to do is: thin the potatoes with milk (they will thicken a bit when cold), put them in a baking dish, cover with butter slices and bake at 350°F/180°C for about 10 minutes or until warm. Store them in the fridge for up to 3 days.
Calories = 1 serving (1/4 of the recipe). This is only an estimate!