Given the circumstances of the person you are cooking for, if it helps with the immediate necessary weight loss, all the better. Re-education later for lifestyle changes must follow.
I agree on the soups - heaps of variety there. Asian style soups utilising what's allowable on the diet Also stir fries. Although oil is out, you can lube the pan with some Pam, get the vegies frying, then add some non-fat, low salt chicken stock, or use veg stock. Poach the lean meat portion in the liquid, or cook the meat first on Pam, brown, remove from pan, do vegies, add your stock, re-add the meat to cook thru. You could use potato starch to thicken, if that's allowed.
Skewers of meat and veg flavoured with lemon juice, spray with Pam, broil or grill on bbq. Serve on bed of steamed veg (cabbage is a good "eye" substitute for pasta).
Lots of spices - paprika, pepper (is salt allowed? if not use lemon/lime juice), cumin, curry powder etc.
Dips like tzatziki, or salsas, along with crudite for dipping. Keeps the hands busy, fills you up, lots of crunch to replace that cracker crunch :)
Is cheese allowed? I would imagine probably not, but a little grated parmesan on baked vegies for variety should be ok. Parmesan is very strong tasting so you need nowhere near as much as say mozarella or cheddar. Baked jacket potatoes with plain low fat yoghurt, chives. All sorts of stuffings....grilled red peppers, olives...
Are eggs allowed? Or is it only the yolk which could be an issue? There's various threads here which deal with using excess egg whites, and if you can use splenda, then there are a number of deserts you can make, incorporating fruit too.
Deserts - "no sugar" jellies with allowable fruits. Fruit smoothies with greek yoghurt (is that allowed?)
Good luck with it - its not an ideal long term solution, but I do hope it works, and I hope this helps a bit.
DC