Wikipedia
Vazhaithandu
Vazhaithandu refers to banana stem or plantain stem and is used in various soups, stews, curries, stir fries and other dishes ( thogayal, pachadi, poriyal and koottus). It is also used to make poriyal ( subzi), juiced, used in a version of raita.
The 1968 Tamil film Panama Pasama featured the song Vazhai Thandu.