To explain the context, today I talked with a security officer down in my dormitory, and she gave me a picture of a food that she believed came from my country. I then wanted to ask her, "When did you try that?" by saying, but she did not understand it despite my trying to say it with the right tone three times. What is the mistake in my phrase, and how can I say "when did you try that" like a native Chinese?
And also, to add, how do natives usually call a security officer?