As you might have seen from my history I had a very bad advisor who deliberately underpaid me, stole my research work and undermined my career at multiple phases.
Now I am done with my university and leaving next month. A professor in my department had been very supportive of me during these times, giving me advice on how to handle this situation, gave me recommendation letters to apply for PhD programs at other universities and also got me a internship. I just want to thank her for her help. I usually would have got a champagne or something but I know she doesn't drink alcohol. Any advice?