Thank you for that description.
I think I would rather put earthy than citrusy in my personal bowl o’ red, even if it’s not from the correct hemisphere.
Mine is my own personal take, anyway…what I call “rust belt chili.” Not only regular ground beef but (minimal) tomato, onions, and BEANS. DARK RED KIDNEY beans. Plus assloads of chile.
Taste is very subjective – to me it has hints of citrus, but other sites claim that it tastes “peppery.” Epicurious says Mediterranean oregano is “Sweet, with anise notes” and Mexican is “grassy with citrus notes.” Spruce eats says it’s stronger flavored (which I would agree with) and to use it in chili powder for its “strong, peppery flavor.” I personally would actually call Greek oregano "peppery. Penzey’s simply says it’s “strong, pungent and less sweet.” Savory Spice Shop.com says it’s “a bit stronger, less bitter and less minty” than Greek. The Spice House claims it’s earthier than Mediterranean (I would say the opposite.) Serious Eats says Mexcian oregano has an “aromatic, bright unmatched by Italian oregano” (spot-on to how I taste it.)
So, yeah, try it for yourself. The descriptions don’t all completely agree with each other and the way you perceive it may differ. I prefer it for chili and the like, because I’m used to its flavor in Mexican dishes in particular and associate it more strongly with chiles than European oreganos.
Doubling back to the subject to this thread – I should add that marjoram is not exactly unusual in Mexican cooking, so maybe that’s where the BBC got the idea from. Or maybe they think marjoram is a closer substitute to Mexican oregano. (I can maybe kinda sorta see that.) At any rate, despite its use in Mexican cuisines, I’m not really finding any support for it being used in a Tex-Mex originating dish like chili or in any of its regional spinoffs like “Cincinnati chili.”
Hence my query. I’d apparently copied the BBC recipe into a file I keep on hand, mainly because I don’t have access to any of the peppers that should be in any good chili recipe. So mine’s not going to be the real stuff, anyway, but I noticed that no other recipes seem to call for marjoram, so I had to ask.
They pronounce it “or-uh-GAWN-oh,” too.
Thanks to all for your contributions!
Oh, I almost forgot to add, for the benefit of would-be, at-home chili makers:
Slow cookers don’t produce enough heat to properly cook raw (hydrated) red beans. There’s a harmful substance that has to be broken down, and slow cookers don’t usually or ever get the job done. Look into it or ask here.
Well, some would say the fact that you have kidney beans in it would make it not the “real stuff.” 
But, no, you don’t need access to any specific peppers to make a good chili. Sure, if you can, make a nice powder with anchos and guajillos and stuff like that, but you should be able to find what you need over there in Europe. I used to make it when I lived in Hungary all the time, and it tasted like good chili. Just use a good mix of various powdered chiles and paprikas (remember, paprika is just another type of powdered chile.) I would pick a sweet Hungarian paprika as my base, then add the heat from various types of dried hot peppers I could find (the Indian store would have Kashmiri chile powder, so I’d use some of that; Hungary has some hot paprikas that near cayenne peppers in terms of heat, so I’d use that. Also, maybe some ground up hot cherry peppers for a bit more variety. Maybe a little bit of smoked paprika as well, for just a whisper of a smoke kick, but I don’t like my chilis particularly smoky. That said, in America, I do often add a bit of chipotle which does the same thing.)
You can use whatever indigenous chile peppers you have along with paprika (and where you’re at there’s some very good ones) to come up with a chile powder base that has a good mix of depth of flavor, fruitiness, earthiness, and heat.
And, yes, there are other recipes that also use whole dried chiles that are toasted, rehydrated and blended and/or fresh chiles, but your bog standard chili is fine with powdered chiles + cumin + beef + garlic. The purist purists don’t even add tomato or sometimes onion. It sounds like you’re doing more a general style chili with beans, and I’m sure you’ll be fine using whatever chiles/paprika you have access to.
Everybody makes chili. I’ve helped judge chili cook-offs and the thing that makes it easy is that 90% of the entries taste identical and can be eliminated on the first round of tasting.
Put whatever you want in your chili. Make it distinctive, make it yours.
I’m not sure what to put marjoram in, it tastes more minty to me than anything else.
I’m the guy who puts too much oregano in his chili! And it’s from the wrong hemisphere! BOO-YAH!!!
Maybe some sage would be appropriate here. Smudge it and make the negative energy disperse.
I generally use it in stews, soups, and sausages. I can see the mint connection, but I don’t really think of it as minty. I find it pairs well with caraway seed, so if I’m doing kind of a German-Austrian style goulash/goulash soup, I’ll use both caraway and marjoram in it (whereas I won’t in a Hungarian style, though there are probably parts of Hungary that use it as well.) It’s one of my basic spices for bratwurst (along with white pepper, caraway, and mace), and there’s a number of Polish soups that use it (like zurek/sour rye soup.) One of my Italian friends seems to use it a lot in his sauces, though I don’t use it for red sauce myself.
Another BBC oddity I noticed as I googled marjoram, trying to conjure up other uses:
It is not called “oregano” in the USA. “Marjoram” is called “marjoram” in the USA. “Mexican oregano” often just goes by “oregano” (the Mexican brands around here all just say “oregano,” so you have to know that they’re Mexican brands or look at the place of origin) but I have never in my life heard of marjoram being called “oregano” in the USA.
I agree that marjoram is kind of cool like mint where oregano seems to have more of a spicy heat.
It’s essential in my split pea soup which starts with the broth left after simmering corned beef. Almost time to start stocking up during St Patrick’s Day sales.