I was able to find this article discussing the subject and even offering a few ideas for how to get tea foam intentionally:
https://www.dreamycup.com/why-does-tea-foam/
The ideas they shared were:
- Pour your water from a significant height
- Shake your tea vigorously in a bottle
I'm not sure if this will result in the same type of foam you enjoy so much, but they're easy methods to try.
Interestingly, they also note that the natural occurrence of tea foam was considered a treasure in ancient China, and a sign of imminent love in England. Some even say it means you're soon to come into money. So you are most definitely not alone in your love of tea foam!