We are another veggie family who struggled when they were on school meals as there were never enough veggie options to go around, the dinner ladies apparently thought fish was a vegetable and my boys were fed either a salad wrap or baked potato almost every day. (Ds1 retches when he eats potato so they stood over him while he struggled to force it down!)
They also used to do strange things like give them a salad wrap with a plate full of overcooked, cold carrots, peas and sweetcorn. Apparently to make sure they get a 'balanced' intake.
I have been to 'bring your parents to lunch' day three times and was horrified every time at the poor quality of the food which was barely luke warm, overcooked and frankly completely unappetising, when surely they must have been pulling out all the stops bearing in mind the parents were going to be eating it as well.
Bizarrely they have won awards and some competitions for there meals - I honestly don't have a clue how.
On top of all that the dinnerladies were absolutely horrible to ds1 when he had only just started reception. Rather than helping him make his choice they shouted at him and told him to hurry up and stop holding up the queue. The poor little lad was so small he couldn't even see over the counter to tell what was on offer and has sight issues anyway so should have been given extra help - they did know about this. That coupled with all the noise in the echoey hall so he couldn't properly hear what they were saying to him meant he ended up just freezing in panic as he approached the counter. When I went to his 'bring your parents' day they had the audacity to say in front of me 'oh, here he comes, Mr Slowcoach Indecisive' and believe me, it wasn't said in a nice jokey way they were actually being bitchy to a four year old! Needless to say he went on to packed lunches the next day and has never looked back.
So now I give both of them a healthy packed lunch with a home made healthy treat such as apple, oat and raisin muffins or something similar each day. At least that way I know they are getting a good quality, well balanced meal that they are happy to eat and will finish.