This is from a very old Bon Appetit Barbecue magazine. I've made it many times for special occasions - most recently tonight, for New Year's Eve with steak and salad. Can easily be halved for dinner for two.
Preheat oven to 400 degrees (200 C). Butter 9x13 inch baking dish with 2-inch high sides.
In saucepan, stir cream and Boursin over medium heat till Boursin melts and mixture is smooth (alternatively, heat cream in large bowl in microwave till very hot, then mix in Boursin till blended smooth).
Arrange half of sliced potatoes in baking dish in slightly overlapping rows. Generously season with salt and pepper and pour half of cream mixture over.
Repeat with remaining potatoes and cream.
Bake until top is golden brown and potatoes are tender when pierced with knife, about one hour.