Hello Folks, I have been doing drop off catering for a little while now, but was just asked to cater a halloween party for 700 people, the person running the party will be absorbing the food cost, i'm mainly doing this to see If I can. There will be a professional kitchen on site, he will supply the help to assist me in the prepping, cooking and serving, I'm just looking at what your suggestions would be on raw product, the menu he asked for is: roast beef sandwiches meatballs and sauce for either sandwiches or plated 40 lbs of potato salad and coleslaw The recipes I'm good with as well as the condiments, I guess I only need help in determining how much raw beef and what cut would yield the most. I have a restaurant depot local to me. Any help friends would be greatly appreciated! New to this, please be helpful, trial by fire I guess!