Add potato and 1/2 tsp salt to a large saucepan and cover with cold water by about 5cm.
Place lid on saucepan and place on stove over medium high heat.
Bring to boil then reduce heat to medium and simmer for about 15-20 until potato is cooked and tender. Use a fork to test. Note: it is important the potato is tender, so cook for additional time if required.
Remove from heat, drain water from saucepan then transfer potato to the large bowl of your Kitchenaid stand mixer.
Add butter and using the paddle attachment commence beating potatoes on low setting (speed 2). Beat until fully combined and a smooth mixture is created. This should only need a minute or two.
Gradually add warm milk and continue beating until fully combined. Increase speed by 2 settings to finish. Don’t overbeat.
Add black pepper, 1 tsp salt & chives (optional. Return speed to setting 2 for a short light mix through.