May I suggest a main course that gets its liquid from the firmented grape? ;) This is the Anthony Bourdain version of the French classic (and a personal favorite of mine).
Never, ever lace a food product with a psychotropic like cannabis and serve it to unsuspecting persons. You don't know if someone is allergic or will have a bad reaction of any kind to it.
That is a business lunch and what they really expect is for you to feel sorry for the kids and use your own money. $1.50 per person is stupid. I have been to lunches for TSCC mucky mucks and the meal was catered and the budget was $25 per person.
I believe you are in England - The best thing you can do is serve real American style hot dogs and hamburgers. The children at the meeting (120 of them) will love you.
Sorry, but English food is gross. Fish & Chips on newspaper however, is way cool.
I was tempted to get loads of pizzas some dortios and dip and loads of pop (soda) with non laced brownies cookies etc for afters. Just like I would provide for teenagers movie night but that isn't healthy enough. Some of these guys and girls look like skeltor they need a good feed! They can expect me to put my money in all they want I will suggest they use some of my tithing money to make up short fall.
What a ridiculous budget! You might consider Chinese fried rice and a Chinese main course heavy on vegetables and light on meat. I would also stick strictly to the budget. Let them see what that money buys.
I am to afraid to ask for donations. I fear they would donate loads for the rightious missionaries; whereas I got 3 easter egg donations for kids at the food bank for the poor. I think I would loose all faith in humanity. Also I think the brainwashed servants of the Lie LTD company have a sh!t enough deal with out having to deal with some old dears tinned peaches from the early 70's.
The ridiculously small budget is the Head Honcho's way of assuming that you, and other "volunteers," will actually pony up cash out of your own pocket to buy the ingredients for a decent dinner.
You could immediately email them back with William Tecumseh Sherman's statement regarding another tough job, the US presidency: "If nominated, I will not run; if elected I will not serve!"