A children’s book I read in the early-to-mid 90s; could have been published earlier. A school cafeteria serves chicken (I think), possibly tenders. The chicken is delicious and possibly addictive. A student, male, investigates the cafeteria situation and, towards the end of the book, discovers that the chicken is made with a poisonous ingredient hidden in the cafeteria kitchen that gives it its flavor/addicting quality; the ingredient is stored in a large vat. There’s a fight between the hero and the evil cafeteria employee. The book is NOT Bone Chillers: Back to School or Eat Your Poison Dear.