Peel the potatoes with a vegetable peeler. Remove any eyes or dark spots. Rinse them under cold water. Cut large potatoes into similar-sized pieces for even cooking.

Place the potato pieces into a large pot. Cover them with cold water. Add one teaspoon of salt. Starting with cold water helps the potatoes cook evenly from the center.

Bring the water to a gentle boil over medium-high heat. Cook the potatoes until they are very tender. A fork should slide through each piece easily without resistance.

Drain the cooked potatoes thoroughly using a colander. Let them sit for one minute. Removing extra water prevents watery mashed potatoes and helps create a richer final texture.

Place heavy cream and butter into a small saucepan. Warm them over low heat. Do not boil the mixture. Warm dairy blends more smoothly with freshly cooked potatoes.

Return the drained potatoes to the warm pot. Add the melted butter and warm cream. Mash gently until the potatoes become soft, smooth and fluffy.

Add sour cream to the mashed potatoes. Stir gently until it blends completely. Sour cream gives the dish a creamy texture and mild tang that balances the butter.

Add salt and black pepper gradually. Stir gently after each addition. Taste the potatoes before serving. Adjust the seasoning until the flavor tastes balanced and satisfying.

Finely chop fresh chives and sprinkle them over the potatoes. Stir some into the mixture for extra flavor. Save a few pieces for a simple garnish.

Transfer the mashed potatoes to a warm serving bowl. Place a small piece of butter on top. Garnish with chives and serve immediately with your favorite main dish.