Peel the potatoes using a vegetable peeler. Remove any dark spots or eyes. Rinse them under cold water. Cut large potatoes into similar pieces so they cook evenly.

Place the potato pieces into a large pot. Cover them completely with cold water. Add a little salt. Bring the water to a boil, then cook until the potatoes become very tender.

Test the potatoes with a fork before draining. They should break apart easily. Drain them well using a colander. Let them sit briefly so excess water can evaporate.

Add the heavy cream and butter to a small saucepan. Warm them gently over low heat. Do not let the mixture boil. Warm ingredients blend more easily with hot potatoes.

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

Add the sour cream to the mashed potatoes. Stir gently until everything is combined. Sour cream adds a slight tang that balances the rich butter and cream.

Add salt and black pepper according to your taste. Stir gently after each addition. Taste the potatoes before serving. Adjust the seasoning if needed.

For an extra smooth texture, add a little more warm cream. Avoid adding too much at once. Stir gently until you reach your favorite mashed potato consistency.

Sprinkle chopped fresh chives over the potatoes. Stir some through the mixture if desired. The green herbs add freshness and a lovely color.

Transfer the mashed potatoes into a warm serving bowl. Add a small piece of butter on top. Serve immediately while the potatoes are hot and creamy.