There is a book called Lobscouse and Spotted Dog: Which It's a Gastronomic Companion to the Aubrey/Maturin Novels, that not only describes all of the foods in the novels (and movie), even gives recipes.
https://www.amazon.com/dp/0393320944/ref=cm_sw_r_cp_awdb_imm_HAAEEV3A5HE1ZH7E71NR
It's a fun book. I really want to try the Drowned Baby desert.
I don't know if you're aware, but there is a marvellous companion book to the series called "Lobscouse and Spotted Dog" containing recipes for every food mentioned in the series.
Amazon link here, obviously also available from other retailers.
Personally, I have made figgy dowdy (it's very similar to spotted dog) a number of sauces, Lobscouse and a sea pie following their instructions. Oh, and quite a lot of the cocktails.
It's a charming book, very much in the flavour of the novels, and I can't recommend it highly enough. As a bonus, there's an intricately worked out time line which will reveal just which Midshipman was responsible for the theft of Stephen's madder fed rats. (Yes, there is also a tested recipe for rat in onion sauce... Madder optional.)
Fun facts: Norwegian immigrants to Liverpool brought lapskaus to Britain, where it was Anglicized to "lobscouse" (British sailors may have also popularized the dish). Lobscouse’s association with Liverpool eventually resulted in the local accent and dialect being named the shortened "scouse" (with which non-Brits may be familiar from the Beatles).
You might enjoy the story. This would have been during POB's tour of the US, the time he had dinner aboard the U.S.S. Constitution in Boston with William F. Buckley and Walter Cronkite, 1999 maybe. I think Patrick Tull was there too. I was active then on the POB Usenet group and one of the members invited the others to his home near Boston for a party in celebration. I don't know how he got Patrick Tull to come.
I showed up with a couple bottles of sparkling wine and some homemade cheese straws and found myself in a very nice kitchen meeting the "amiable sluts", the mother and daughter team who wrote Lobscouse and Spotted Dog. Amiable indeed! They praised my cheese straws, which went straight to my heart. And then, wafting over our heads, there was The Voice. I followed it to its source and found Patrick Tull standing in a group of admirers and poured out on him a brief flood of fanboy geekieness. I had already spent so many hours with his voice.
Later he favored the company with a performance of the Off Hats! piece. Very moving, as always. The party showed what you know already, that POB fans are some of the nicest people.
You might be interested in Lobscouse and Spotted Dog, a book written about the food mentioned in Patrick' O'Brian's Aubrey Maturin series of historical novels concerning the Royal Navy in the time of the Napoleonic Wars.
The officers and ratings ate huge meals especially before a battle.
Lobscouse Sea-Pie
Strasburg Pie
Frumenty Syllabub
Whipt Syllabub Syllabub from the Cow (Windsor Syllabub)
Spotted Dog
Christmas at Sea: Sucking Pig Roast Pork Mince Pies Christmas Pudding
Kickshaws
Toasted Cheese
Comfits
Breadfruit Biscuit
Breadfruit Toast
Maids of Honour
Shrewsbury Cakes
Ratafia Biscuits
Made-Dishes and Puddings
Curry Pilaff
Lacquered Duck Bathed in Rich Sauce
Plum-Cake Jam ...
See /r/aubreymaturin
Not an answer to your question, but just to be sure that you are aware, there is a POB cookbook.
May I suggest a prodigious fine book, Lobscouse and Spotted Dog, which I find answers handsomely when one is sharp-set after a long watch.
Look inside Lobscouse and Spotted Dog for some proper British puddings.
The winner, hands down: https://www.amazon.com/Lobscouse-Spotted-Dog-Gastronomic-Companion/dp/0393320944
Also called "drowned baby". Enjoy. You can make spotted dick and shit soup using these recipes.