Generate a colorful and engaging educational mood board with the theme of food chain processing. The center focus should be the step-by-step creation of a sandwich, starting with the growth of grains for bread, followed by the farming of vegetables and poultry, and cumulative in assembling the sandwich. It should be designed in a child-friendly style, appealing to a school-going audience. The mood board should contain various related images such as, a grain field, a farm with vegetables and poultry, loaves of bread, fresh vegetables, cooked poultry, and a completed yummy sandwich.