You're right, of curse, but the sauce that accompanies it is also eponymous, hence my recommendation to the OP. Legions of manufacturers and restaurants, takeaways and others sell Katsu curry sauce. Waitrose is a good one.
I sometimes find adverse reactions to some takeaways, but I usually attribute it to super high salt levels and over ordering leading to over eating. Tends to be takeaway curries that are worst offenders as high spice, sugar and fat leads to huge handfuls of salt I suppose.
And this an important point. It is not foreign manufactured substance. Chemically it is the same.
So you agree with the eponymous "Road tax" that everyone spouts off about? Just because the legions of Joe Blogs say they pay it, does that make it true?I love the way that pedants are almost always wrong
The important thing to notice is that Waitrose sell Katsu CURRY sauce, not Katsu sauce....
OP, note this important clarification, lest you simply look for Katsu sauce, whereupon you may get another type of sauce completely as opposed to a curry-flavoured one, like, er, well, that's all that's typically sold as katsu sauce, but it's very important to be on the look-out for imposters that might not be a mild curry flavour.
That's the other thing I love about pedants
Popular down here only it's made with real cats
That's the other thing I love about pedants
I used to be one (least I was told by others 
), but you know what, I try not to be these days, and use what's common language and don't worry too much about spelling etc., just about whether what someone else or me are saying is understood by the recipient, because that's what really matters.
Om and indeed nom. Pussy Katsu indeed (see what I did there? Oh well, please yourselves!)Popular down here only it's made with real cats
