Brie en croute is simple. Take a wheel of Camembert (they're the little ones) or anything up to a 1-kilo Brie wheel (they start to show up in the run up to Thanksgiving most places) and a package of frozen puff pastry. Thaw your puff pastry according to the package instructions. For a larger-sized wheel, you may need to roll the pastry out to be larger. Wrap cheese in pastry. Bake at 400-425 for 25-30 minutes. Let it stand for a bit after you take it out of the oven, because molten cheese is no fun for your upper palate.
Former cheesemonger at your service!
If you want, you can split the cheese horizontally before you wrap it and spread fruit preserves and sprinkle nuts of your choice on the inside. But many cheesemongers think to do so is sort of déclassé.