by luck i saw how my local TA do the garlic slithers - they pre fry (am pretty sure in butter) and then add them cold on top of the curry before putting the lid on the carton.
with this and Secret Santa's chilli sauce i felt i could give the sylheti a go. i don't think it's far off and can't really see a need to change it. obviously any ideas - very welcome.
Sauce recipe moved to here by CA: https://curry-recipes.co.uk/curry/index.php?topic=4333.0