Hello! i believe the grammatical word for для шаурмы within the sentence is attribute (определение). It answers the question which? ингридиентов каких? - для шаурмы, attribute usually qualifies the noun, but not necessarily the subject of the sentence , like in this case the subject of the sentence is рис , predicate is skipped ( but we are assuming its verb есть) and ингридиентов is object.
There is a book called "Практическая грамматика с упражнениями" , it explains well Russian Syntax, its a bit advanced though. Good luck