For experienced colleagues, I always ask 'What does an outstanding lesson look like to you?', 'Can you describe for me your favourite teaching strategy?', 'How do you intervene if a pupil in your class is underachieving?' (for this one, I then go on to focus on different levels of underachievement eg A* candidate getting high Bs, C/D borderliner, D grade student getting E/F etc).
I also ask about planning for mixed ability classes at KS3 and differentiation, assessment for learning, approaches to homework, extra-curricular opportunities you want to explore/offer, etc etc. I usually end on 'What can you bring to the department, in addition to what you bring to your classes?' for which I'm looking for things like energy, a positive outlook, support for new staff, loyalty, creative thinking, organisation and a willingness to tidy the stock cupboard!
Good luck with the interview. Focus on energy, high quality outcomes, relationships with pupils and colleagues. If you can, squeeze in a bit about the learning environment as anyone leaving will probably have let their classroom start looking a bit rough and they'll like the idea that you can reinvigorate the space.