TASK DEFINITION: You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
PROBLEM: Category: WAITER! 
Clue: To get us started, a serving of this dish named for an oilman: oysters topped with spinach & then baked

SOLUTION: oysters rockefeller

PROBLEM: Category: MOTHER GOOSE 
Clue: It's the type of nail referred to in the nursery rhyme "All for Want of a Nail"

SOLUTION: a horseshoe nail

PROBLEM: Category: "AZ" I WAS SAYING 
Clue: The title of this 1969 Alfred Hitchcock film comes from the code name of a French spy ring

SOLUTION:
topaz