Add the potatoes to a large pot, cover them with cold water. Bring the water to a boil, reduce the heat until simmering, and cook the potatoes until tender- about 15-20 minutes. Drain the potatoes and then transfer them to the bowl of a stand mixer.

Add the butter to the potatoes. Using the whisk attachment, whip the potatoes for 30 seconds. Pour in the half and half, and whip JUST until the potatoes are almost completely smooth.

Use a spatula to fold in the Boursin cheese until completely incorporated. Salt & pepper, to taste.

Scoop the mashed potatoes into bowls, or onto the desired serving plate. Sprinkle with the parsley, and serve immediately.