They won't ask you broad themed questions. I had a few authors on my CV that I like and who's books I have read, they asked me about one of them. I had mentioned I worked in a tax department of a firm they asked me a question on tax policy, they also had an option on a specific place that I had travelled to. The final was about a sports club I was involved in. Easy topics if what you wrote on the CV is true, they tend to be relitivly specific but give you a bit of room to work with. Main thing to note is 5mins goes very quickly you probably won't have said everything you want to, so planning what to say and getting it done within the time limit imwas the hardest bit from what I remember.I believe you are given a choice of 5 topics from your CV. This is at MB.
Out of interest - do AOSB give you a specific title or is it a broad topic. For instance, if I mentioned I studied biology, would they ask for a lecturette on a ‘biology topic’ or would they pick a specific topic... ‘discuss mitochondria’.