Indian festivals have a close relationship with food. There’s always a vegetable, grain, meat dish that’s traditionally eaten on a specific festival whether it’s til gud or khichdi on Makar Sankranti, rewdi-moongfali on Lohri or sewai on Eid.
In our house, there hasn’t been a Diwali when my mother has not cooked jimikand, also known as sooran or elephant foot yam. In eastern UP it’s a tradition to eat jimikand around Diwali. There’s an interesting reason behind it and Sangeeta Khanna has nicely described it on her blog banaraskakhanha.com. Yam grows from corms (bulbo-tubor) and after harvesting it grows again from the leftover corms in the ground. This property of the vegetable falls in line with the ideology of storing and increasing wealth during Diwali and hence considered auspicious.