Peel the potatoes, then use a sharp knife to quarter potatoes.
3 pounds potatoes
Place potatoes into a large pot and fill with cold water until the potatoes are all submerged.
After that, place the pot onto a burner set to high heat to bring it up to a boil.
Once the water is boiling, reduce to medium heat. Boil potatoes until they are fork tender.
Pour the potatoes carefully into a colander set over the sink. Drain water completely.
Place the pot back onto a burner set to medium.
Then, melt the butter in the pan, then cook the garlic for 1-2 minutes until golden brown.
3 ounces unsalted butter, 3 cloves garlic
Return potatoes back to the pot and use a potato masher to mash potatoes until they start to break down. You can leave them lumpy or mash a bit more for a creamier texture.
Season potatoes with salt and pepper.
1 ½ teaspoon salt, ¾ teaspoon white pepper or black pepper
Next, use a rubber spatula to mix in the sour cream and heavy cream. You can further mash the potatoes if you like but stop as soon as you reach your desired consistency.
⅓ cup sour cream, ½ cup heavy cream
Finally, stir in the shredded white cheddar cheese.
6 ounces shredded sharp white cheddar cheese
Transfer to a large bowl or other serving dish and serve hot.