If it's crucial for your field, are there other people in your department effected too? If so, it might be worth talking with the department person in charge of research students, to see if they can do anything. There might be someone in your dept using that method / technique, who isn't able / willing to teach it for the whole faculty but might for their own students. Otherwise I'd look up what the formal complaints procedure is at your university and start using it. I've noticed that if you complain formally a lot more notice is taken than if you just have an informal moan in an office. If then you have to escalate, you can prove that you've followed procedures but not have a satisfactory reply.