Idk isn’t it just that the name is misleading?!

It looks like a Windows XP activation key!

Salt, Fat, Acid, Heat by Samin Nosrat does this. It begins by introducing the eponymous 4 elements at length then provides a decision tree to help you work through the recipes at the back according to the gaps in your experience.

It’s not specifically focused on Indian food but does contrast flavour profiles from different countries. For British Indian Restaurant Curry I’d recommend Dan Toombs “The Curry Guy”. It’s not written like a textbook but I’ve learned loads of tricks from it (e.g. base curry sauce/ freezing fried paneer for later, yoghurt marinades etc).

It might just be that they dried up in the hot weather. If so they’ll uncurl now it’s rained.

You might also want to check for ants breeding black fly on the underside. They suck the moisture from the leaves causing them to curl over. You can usually just scrape them off with a wet finger.