It depends on the curry recipe, but you probably could add vinegar to it... just so long as you avoid anything cream-like. (But it would DEFINITELY clash with the bananas, and putting a whole jar of uncrushed coffee beans and unpeeled bananas would have already ruined it.)
Eh~?Oh! So you can add vinegar in a curry too?'Sup, Samidare!
What do we have for lunch today?VinegarI-Is that so...No way~!Ah, that's right!It's curry~ ♪Ah!
I heard about that too.Oh!
It looks really tasty!!Oh...Really, Suzukaze-chan~But the most important secret ingredient has got to be love towards Admiral, right? I heard that putting coffee in will bring out a deeper flavor! I heard that putting chocolate in will bring out a richer flavor! Putting bananas in will... err... what was it again? I forgot!!