For those who have issues with overly large restaurant portion sizes, I highly recommend getting a box and putting half in the box when it arrives. The other trick I've used a fair bit is to find a plate that I can share with a friend and split it that way.
Athena Scalzi talks about her experience getting a box with her meal and it's worth a read for those who might be struggling.
https://whatever.scalzi.com/2022/12/06/do-you-want-a-box-for-that/