Yum indeed! I also make sure to ask for an extra helping of the (dry) peanut chutney. That and the green chillies are must-haves with a vada pav for me :)
I've always heard it referred to as "Dana Chutney", Dana being a contraction of Shengdana.
I don't know if it's the same thing as Thecha, though -- but it does fit the description. I'm wondering if this is a geographical difference in culinary terminology :)
Do you mean thecha?
https://en.m.wikipedia.org/wiki/Thecha
I have read about it, but unfortunately I did not come across it, despite living in Maharashtra for some years.
Got to say, from the description, it sounds like it would taste quite good.
And could be a good accompaniment to many dishes.