Peel and dice the potatoes. Bring a large pot of salted water to a boil. Add the potatoes and cook until fork tender. Drain, then return to the pan over medium heat. Using a potato masher or wooden spoon, roughly mash the potatoes for 1 minute to remove the excess water that remains.
Remove from the heat and add in the boursin cheese. Use a handheld mixer on medium speed to melt the cheese into the potatoes. Slowly add in the milk and whip until the potatoes are a creamy texture and no lumps remain.
In a small saute pan over medium heat, melt together the butter and cream. Add the Old Bay, chili powder and lobster pieces and stir to combine. Sprinkle with the chives.
Move the mashed potatoes to a serving bowl and pour the lobster cream over the top. Garnish with additional chives, if desired. Stir together prior to serving.