Peel and cut the potatoes into quarters, then place them in a large pot.
Add enough water to cover the potatoes by about an inch.
Bring the water to a boil over medium-high heat.
Cook the potatoes until they are tender, which should take around 15-20 minutes.
Drain the potatoes and return them to the pot.
Mash them using a potato masher or fork until mostly smooth, leaving some texture if desired.
Add butter, milk, and sour cream.
Mash again until all ingredients are well combined and the texture is creamy.
Season with salt and pepper to your preferred taste.
Continue to mix until the seasoning is evenly distributed.