Let me explain about how students serve their lunch. At first, they wash their hands and wear this outfits quickly when morning classesare over. Then they carry food in container. Next, in a group, 5-6 students have their own responsibilities, from serving rice to giving plate or pouring tea. Other students who are not on the duty of lunch serving would get plates and utensils and form a line to wait for their turn to be served.
Some cities employ staff to cook lunch at each school.
But other cities have lunch catering facilities to cook lunch for several schools together and deliver cooked lunch to schools before lunch time. I got the information that other countries have school lunch. School lunch originates long time ago. It started in Munich, Germany in 1796 to help poor students. It took effect in Paris, France, in 1849, and in the US in 1885.