This is verbatim from_Best of Friends, Ect. Ckbk_

"An old tried & true way to cook beef. It is so aromatic that you
will hardly be able to contain yourself before the cooking time
is up & you can taste test. Originated for cheater cuts of beef,
I prefer to use a top round roast, sirloin or even a nice rump
roast."

Peking Roast (commonly known as Black Beef)

3-5 lb roast
Slivers of onion & garlic
1 C vinegar
Oil for browning
2 C strong coffee
salt & pepper
1/2 C whiskey (optional)

Using a knife to cut slits halfway down through the meat, insert
slivers of onion & garlic. Onions alone may be used if you do
not care for garlic. Put the beef in a glass bowl & pour one cup
of vinegar over it, making sure it runs down into the slits.
Cover & place in refrigerator for at least 24 hrs. Make sure
make lots of slits to hide the onion & garlic.

Next day, discard the vinegar solution & place meat in a heavy
roaster and brown in oil until nearly burned on both sides.
(Kitchen will smell like it's burning) Pour two cups of strong
black coffee over the roast. Add two cups of water & cover. Cook
this slowly on simmer for 6 hours on top of stove. DO NOT SEASON
until 20 minutes before serving, then add salt & pepper. Nothing
else.

I add 1/2 C whiskey to the boiling mixture, but you may omit it.
However, I believe this is what makes the roast ever so tender &
the alchohol will cook up & is not noticeable. The gravy is
absolutely the best ever. it may be thickened (as for any roast
gravy) or left as is.

If you cook your roast too fast or if the lid on the roaster is not
tight, you may have to add some additional water-if so-add only one
cup water at a time.

BONUS: Peking Roast can be made ahead of time if you are expecting
guests. The black meat is somewhat different & everyone will ask
for the recipe.

BONUS: Don't be afraid to almost burn the beef while browning...
that's what makes it so delicious & the best gravy ever.

I have never tried this recipe personally, but always thought it
looked quite interesting. Let me know, if you try it.