Welcome to Flyertalk and welcome to the BA forum, speed.skater, it's good to see new people here and I hope that we will see more of you in the future.
As I'm sure you have already seen the photos in the main CE food thread, unfortunately the other European airlines' forums tend not to be as comprehensively served, photos wise, compared to BA. But my own experiences with the European airlines is that the portion sizes tends to be somewhat on the small side compared to BA, though you can sometimes get more bread rolls if ballast is required. That said, the UK is on the edge of Europe so some of BA's trips are quite long compared to those airlines nearer to the centre of gravity. TK, which is also Do&Co has fairly similar portion sizes to BA, maybe slightly smaller, and they too have some longer routes to run.