There are numerous modern recipes for curried mutton, from the Caribbean, and many other places including, still, Britain.
The whole question of the origin of curry and its reception and spread from a Portuguese and British expatriate context is of absorbing interest, but beyond our scope here. Those interested might start with Michael Snyder’s essay in The Takeout two years ago.
Snyner, based currently in Mexico City, writes on a diverse range of topics including food and architecture. He cites the two leading full-length studies (to my knowledge, they are) and adds his own trenchant insights. Another essay, from English Heritage in 2016, adds a further dimension.
In terms of modern approaches to curried mutton, this video on YouTube from a Trinidad-based channel offers an easy-to-follow, evidently authentic recipe.
There are other YouTube demonstrations of this dish, of course each with its own riff. You can find them from Jamaican cooks, from the Bahamas, and elsewhere in the region. I have absorbed something from each, and will put it all to good use soon.
A few years ago in the U.K. two brothers, Craig and Shaun McAnuff, wrote a best selling book, Original Flava. While London-raised, the book draws on the Jamaican cooking heritage of their family.
Their curry mutton pie looks excellent, a combining of traditional curried mutton and British shepherd’s pie recipes. They flavour the potato topping with coconut, which is just the right touch.
Going back earlier in the U.K. but not quite to the 19th century, a news report in 1944 described a mutton curry at a London club before the war, where particular efforts were made to ensure quality. This is underlined by the fact that it was served with a “pale India ale” – at near room temperature.
All indices are good, in other words. I liked the fact that the dish was served with only two “side kicks”, Bombay duck and one other. So often too many choices ruin the honest frank flavours of a characteristic dish. The East India Club, the venue in this case, evidently knew how to do things right, in the context too of what was probably a mid-day specialty.*
The report appeared in the Evening Star of Washington, D.C. The author, “Victory Chef”, wrote other columns on wartime cookery, which I may revisit.
(As Snyder points out, curried dishes were regarded as a novelty by the wider population – Victory Chef reflects this – but were by no means new to American cooking, having been received by the mid-1800s at least).
Finally, returning to the 19th century, the great English cookery writer Eliza Acton gives useful background on mutton per se: the raising, the ideal age, and other tips for the advised shopper. (See pp. 233 et seq).
She was, parenthetically, an acknowledged influence on Elizabeth David; the crisp and authoritative treatment on this subject alone shows why.
*The Club carries on to this day. According to menus on its website, the Indian curry is now of the past. On the other hand, the banqueting menu lists a Thai vegetable curry, so tradition is withal retained. (Maybe the curries change from time to time, as well).