If it weren't for the budget constraint, I'd suggest
North Pond. Its location in the middle of the park is uniquely Chicago. In addition to Sunday dinner, they're also open for brunch on Sundays, which would be less expensive than dinner. Otherwise...
I'd take them to one of our provincial Mexican restaurants -
Mundial Cocina Mestiza in Pilsen,
Mexique in West Town, or
Mixteco Grill in Lakeview. All have Mexican food like they've never seen in North Carolina, with a few dishes that are "mainstream" enough to satisfy the non-adventurous. (Bayless's restaurants are closed Sundays.)
But if Mexican is too exotic (

), I'd probably take them to
Quartino, or maybe
Sable.
Last edited by
nsxtasy on October 28th, 2011, 8:33 pm, edited 3 times in total.