The food service industry is prone to wasting food, but you can do plenty (individually or as an organization) to cut back on wastage. For example, you can donate unused food to local food banks, buy beverages and meats in bulk, and recycle everything from used cooking oils to aluminum.
The best way to fry food service quantities of vegetables (short of deep frying) is to cut them into uniform-sized chunks beforehand, so all of them take the same time to cook. This works best if you do relatively small batches of vegetables at a time.