I own a residential college for 11th and 12th standard students and my student strength is 400.
Its breakfast,lunch,tiffin and dinner for 430 persons daily
See, the menu is as follows : Usually breakfast consists of Puri/Idli/Upma/Vada (any one) plus sambar/curry (any one). Lunch consists of Dal, Rice and a curry and a fried type item or a type of chutni. Tiffin consists of Boiled channa with some garnishing/Golcuppa/besan pakoda/milk and bisciut (any one). Dinner : Dal any one type of sabzi.
Now for any type of deep fry we have to use Gas Chullah, for Roti we use coal. The wood is used mainly for Dal, Rice and any type of boiling i.e Potato. So I think if we use hot water then I will use less fuel for taking the water from 70 degree to 100 degree than from 25 degree (normal water temp) to 100 degree. I will see how much I can reduce the consumption of wood, then I will increase the capacity depending on requirement.