Peel and chop the potatoes into 1-inch pieces and place in a large pot with the minced garlic.
4 lbs Russet or Yukon gold potatoes, 6 cloves minced garlic
Add the fresh thyme sprigs to the pot with the potatoes and garlic.
8 sprigs fresh thyme
Add the cream and milk, making sure the potatoes are mostly covered but some peeking above the surface is fine. Bring the mixture to a boil, then reduce the heat to a simmer and stir occasionally until the potatoes are tender, about 25 to 30 minutes.
3 cups heavy cream, 1-2 cups whole milk
Remove from the heat and discard the thyme stems, use a potato masher to mash the potatoes until mostly smooth with slight lumps. Add in the butter, salt, and pepper and stir just until melted and combined.
½ cup unsalted butter, 2 teaspoons sea salt, 1/2 teaspoon fresh cracked pepper
Top with more butter, salt, and pepper, and fresh herbs as desired for serving.
additional salt and pepper to taste