I mostly base this on reading Dickens, but I thought the traditional Christmas dinner was goose in England, or the UK as a whole, and that in the US, it morphed to turkey.
Personally, when we lived in Manhattan, we always got Chinese. I think there was actually a kosher Chinese place in the area where there were a lot of Jews, but don’t quote me on that-- I just know my aunt and uncle ate there, and they were pretty strict, also the place had sweet & sour chicken, but apparently not pork. I certainly think a kosher Chinese place could’ve survived in the area where I lived.
Once we moved to Queens, I don’t remember that we ate anything in particular on Christmas. But there were some Jewish-owned stores that would’ve been opened, so we could’ve had anything.
In Indiana, we actually do have to plan ahead, because store are closed from like, 5pm Christmas eve until noon on the 26th. DH talks me into Chinese sometimes, even though there’s no kosher Chinese restaurant around here. I just order the tofu & vegetables, and cross my fingers.