Are there any top-notch practitioners who actally teach substantive, core courses in any law school? Not merely advanced electives or seminars - but something that 1st/2nd/3rd year students can also benefit from in terms of core understanding?

Kumarjit Ray used to teach Corporate Law 2 and Clinic at NUJS. He was quite good at it too. However, he has rejoined the industry since. AK Rai teaches at NLUD still. Rahul Singh at NLSIU.

Mihir, Jasmine Joseph, Radhika Chitkara at NLS

Bump… especially in commercial laws!

Shreya Rao used to teach core courses in tax for several years while working with Nishith Desai. That was for senior batches though.

Rahul Hemrajani at TNNLU, currently in NLS. Was a Tax Litigator at LKS Bengaluru.