Wash the potatoes and cut into quarters. Place the potatoes in a large saucepan or a Dutch oven and cover with water. Bring to a boil. Reduce heat, cover, and cook until fork tender. Cook time should be around 10-12 minutes.
Transfer the cooked potatoes into a large bowl. Add butter, sour cream, heavy cream, salt, and pepper. Mash together until the potatoes have reached your desired consistency. To make them thinner, add additional warmed heavy cream. Season additionally with salt and pepper to taste.
Notes
Cut the potatoes into uniform quarters to ensure even cooking. This guarantees that all the potatoes will be fork-tender at the same time, preventing uneven texture in the final mash.
To avoid overcooking, start checking for fork tenderness at the 10-minute mark. Overcooked potatoes can become waterlogged, affecting the final consistency of the mash.
After boiling, drain the potatoes thoroughly to eliminate excess water. This prevents the mash from becoming too watery and ensures a rich and velvety texture.