I don't know sh*t about Brooklyn other than "It's Not Manhattan" and I'm looking longingly at vehicles.
From my exploring, every produce store with Arabic/Devanagari/Pashto/etc signs for 20 blocks down Coney Island Ave. below PP has five varieties of chiles and bitter melons and okra, definitely Indian-type fare. Spices galore. But no papads. Or fresh curry leaves.
The rest of the stores around here seem to be more Russian Polish Jewish and Mexican. Nothing that would sell curry leaves, to be sure.
I'm new here and my walking radius is tempered by the fact I can hop on a train and go back to the City and shop at my old supplier. Just requires pre-planning or 2 hours roundtrip.
(can't find lemongrass or galangal either, but that's more Malaysian/Indonesian/Thai produce and I've not seen that around here.)