Preheat your oven to 400°F (200°C). Wrap garlic cloves in aluminum foil and roast for about 20 minutes until golden brown.

Peel and quarter the russet potatoes, place in a large pot, cover with salted cold water, and boil for 15-20 minutes until fork-tender.

Drain the potatoes in a colander and return them to the warm pot, covering with a lid for 1-2 minutes to steam dry.

Mash the potatoes in the pot, adding butter and cream cheese while still warm until smooth and free of lumps.

Squeeze roasted garlic cloves into the mashed potatoes and stir in sharp cheddar cheese until melted.

Gradually pour in warmed whole milk or heavy cream to achieve desired creaminess, then season with salt and pepper.

Serve in a dish, garnished with freshly chopped parsley, while warm.