As others have said, the World Foods section in the supermarkets - they do major on Indian subcontinent and Far East - but plenty of West Indies products too, which have Latin connections.
I recommend an outfit on eBay. Their eBay ID is thespiceworksteam. They have an enormous range of herbs and spices, are extremely good value - make that amazingly cheap - and P & P is £0.00! Yep! Nada!
They are also very helpful and communicate readily. They assured me that all their products were genuine imports, so I was happy to buy 3 lots of Spanish pimenton from them, dulce, picante & fumado. These smelled just like the ones I've had from El Mercado Central in Valencia - fresh and full of vim and vinegar ...
I wouldn't be surprised if they did not look kindly on a concerted appeal by expats from the US to bring in spices from Stateside and Latin America.
London has everything, as we all know. In my experience, the best Spanish deli is Garcia & Sons on the Portobello Rd. W11. I've been going there for 30 years and the only complaint I have in all that time is the preposterous increase in the price of Malaga wine - entirely due to a succession of our Chancellors of the Exchequer.
There is quite a large community of Colombians in London and also Brazilians, so their favourites will be available, too.
Looking at the individual ingredients of Adobo [one variant, anyway], it is evident that they are all readily available. I just made up a great sticky paste of it from supplies in from thespiceworksteam, including the extras demanded by a recipe for roast pork I found on the web. A piece of pork is sitting in my fridge now, absolutely thick with the stuff, wrapped tightly in cling film. Should be dynamite.
PS Cilantra = coriander.
