In Atlanta during Passover
If you are a "die-hard" Passover keeper, it might be more difficult to not eat kitniyot. However, if you just have to stay away from wheat products and rice, it will be easier. I suggest somewhere that is heavy on the proteins and veggies. Maybe somewhere ethnic like Mexican that uses corn tortillas, or Asian and skip the rice. Or potatoes.
Suggestions - Pacific Rim might have fish entrees w/ veggies and potatoes. Ray's might have a wide selection of side dishes.
Really anywhere that has selection is key I think.
I really like Mitra in Midtown (Piedmont just north of 5th) and Avra (questionable how unleavened they are).
Hope that helps...