Bring a large pot of water to a rolling boil. Meanwhile, cube the potatoes into 2-inch pieces.
Pour all the cubed potatoes into the water. Boil for 20 minutes or until the potatoes are completely soft.
Drain the water. Add the butter, let it melt. Stir so it coats all the potatoes. Then add the cream, Boursin, Parmesan, salt, and pepper. Use a masher or a fork to mash until smooth.
Taste the mash. Add more salt if required. Sprinkle on the chives and serve.