To make the roasted garlic, preheat the oven to 400˚F. Place the garlic in the center of a square of tin foil, then drizzle with olive oil and season with salt and pepper. Wrap the garlic tightly in the foil, then place in the oven to roast for 45-60 minutes, or until the exposed cloves are golden brown and tender. Set aside to cool.
To make the garlic infused cream, combine garlic, cream, butter and thyme in a small saucepan. Place over medium heat and cook just until butter has melted, then remove from heat, cover and let sit for 30 minutes.
Place the potatoes in a large pot and cover with cold water by 1 inch. Add 2 teaspoons salt then place over medium high heat and bring to a boil. Once the potatoes reach a boil, cook for 7 to 9 minutes, or until tender. Drain, then transfer to a stand mixer fitted with the paddle attachment.
Strain and discard the solids from the garlic cream, and squeeze all of the roasted garlic flesh from the head of roasted garlic. Add the roasted garlic to the potatoes, season with the remaining salt and start mixing at low speed. Slowly stream in the infused cream and mix just until the cream has been incorporated and most of the potatoes have broken down.
Transfer to a serving bowl and garnish with chives and black pepper.
Tip: If making these roasted garlic mashed potatoes for a special dinner or big feast, go ahead and roast your garlic and make your garlic cream infusion the day before to cut down on cooking time.