One of the best questions I've been asked by a job candidate. Demonstrates confidence in their ability and willingness to solve problems. And, turns the interview over to the candidate to show their stuff.
If you asked a CFO this question, you might hear, "develop an annual strategic and financial planning system". Your response would include remarkable projects like the budget and cash analysis program you recently implemented at XYZ company. You would go on to give the name of the person to call who thought you hung the moon with that project, and then you would ask the interviewer to go to a special website you created to show samples of this and other great projects.
The point is...you must be able to do more than just answer the question. You must be able to show relevant things...and be able to show things period. You also need to be prepared to show "how" you did it, especially for less tangible things like, service culture improvement, etc. Imagine showing your prospective boss a video of the guest arrival experience you created at your last hotel, or photography of signature food dishes, or maybe just a team photo with you up on everyone's shoulders.
You need to make an immediate impact in a job interview...start by asking, what needs to be done?