Look at the Atkins web site, he has a whole section devoted to holiday menus. For dessert he has a pumpkin pie with a pecan crust that I am dying to try.

For appitizers/ premeal snacks-
Veggie plate with ranch dip
cheese crackers
nuts (in shell with nut cracker)
celery with natural peanut butter or creamcheese mixed with scalloins
deviled eggs

For side dishes-
Green beans
Cauliflower "Mock" mashed potatoes, or turnip potatos
creamed spinich
grilled or roasted zucchini
Gravey made from LC thickner (Xanthum gum, can be bought online as thick and thin or some name like that)
Stuffing made from a mix of nuts or LC bread crumbs (hazlenut or pine nuts, yumm)
Side salad (if they are from germany they may be accustomed to a small salad with meals anyway)


Depending on phase of diet, maybe some sweet potatoes thinned with pumpkin or other "filler." If you can get the toasted marshmallow flavored DaVincci you can maybe fake that marshmellow/yam bake, throw in a little SF maple syrup.

Desserts
The pumpkin pie with pecan crust
crustless cheesecake
Mock apple crisp made with zucchini