Eat mid-day meal first before serving it to students, the Bihar government on Thursday told all primary school principals and cooks.
It also said bad or spurious-looking food ingredients should not be provided for cooking school meals.
Even Education Department officials, inspecting schools, should taste the food being served to children, judge its quality and make a note of it.
The notification, issued by the Education Department in Hindi and published in different newspapers in the state, warned of disciplinary action if the directions were not followed.
The notice also said the principal should also ensure that any sort of insecticide or fertilizer should be stored with food ingredients.
The notification comes after 21 children died and many fell ill in the state after eating a poisonous mid-day meal at a primary school in Saran district on Tuesday.
Police suspect that the mid-day meal at the primary school in Saran that killed 21 children might have been prepared in a container used for storing insecticide.