It’s cockney rhyming slang, it’s best not to think too deep about it
Americans are called yanks, yank rhymes with tank, and septic tanks are a type of tank, so Americans are septics. It’s not exactly flattering but it’s not really as much of an insult as it sounds.
The same kind of logic has them calling “stairs” “apples and pears” because pears rhymes with stairs and apples are kind of similar to pears.
Or “cherry” meaning “lie” because lie rhymes with pie, and cherry is a type of pie.
Few more ingredients but my carnitas have always been a crowd pleaser
I tend to eyeball everything, but usually about a 12oz can of coke, oj and stock until it looks right, one onion chopped up, however many cloves of garlic I feel like peeling and chopping
If the pork shoulder fits I do it in a pressure cooker on high about 2 hours, if it doesn’t I do it significantly longer in a slow cooker
When it’s falling apart, pull the bones out, shred (I like to use a mixer)
Then like you, crisp it up under the broiler, and maybe mix in some of the cooking liquid