Over the last 5+ years at BCG, I interviewed tons of people. As Project Leader, I know exactly what BCG/McK/Bain etc. look for when recruiting their talents.
Here is how I suggest to spend the 60 min (can do it in English, but also German/French as I am native):
1. Quick intro – listening to your specific needs (5 min)
2. Real case from BCG, McK, Berger (25-30min)
3. Feedback on case – how to bring you to the next level (15 min)
4. Questions & answers – about interviews, BCG, the job… (10-15 min)
Of course fully flexible to adjust this agenda to your priorities.
Looking forward to prep you!