I couldn't find a curry block so I used 2 packets of Yo! Sushi katsu curry sauce and it worked fine. I'd probably use 3 next time just because it took so long to reduce with the water to sauce ratio.
I thought I was being smart by doing the tofu first because it needs 15 mins resting but because the curry took longer than expected they ended up being served luke warm. Next time I'll prep everything in advance (including battering and breadcrumming the tofu) then start the curry and tofu at the same time.