All temperatures are for a non-fan oven. For fan-assisted ovens, reduce by 20 degrees.
Pre-heat oven to 240c, and get the shoulder out of the fridge (you want it to be room temperature ish when it goes in, so give it 45 minutes if possible.
Marinate (all ingredients are in amounts of “some, but not too much”, until it tastes a bit sweet and sour without being too salty. They’re roughly in most to least order)
- Ginger beer
- Worcestershire sauce
- Soy sauce
- Brown sugar
- Black pepper
In total, I had about 1 cup (200ml ish) of liquid, and probably would have got away with using about half of that.
Put in dish fat-side-up, and score it. Drizzle the marinate over the shoulder, then rub coarse salt into the scores. Use what feels like too much, this is a big hunk o meat.
Cook at 240 for half an hour. In this time a bit of fat might come out of the meat, but nowhere near all of it.
30 mins at 240 – chop vegetables while you wait
Reduce the temp to 200c, and add any roast veggies to the dish around the meat. Keep in mind that fat will keep coming out of the pork, so you only need to drizzle a little bit of oil on top of your veggies. Or, as I did because I had a decent amount of the marinate left over, get the existing liquid out and drizzle it over the meat again, this time covering the veggies too.
20 minutes at 200c per 500g of meat
In my case that was about 80 minutes.
Remove all the juices again and let them settle in a jug. Either store (for cooking another day) or use (in my case the potatoes needed another 15 minutes) the clearer oil that has settled on top by slowly pouring it out until you start to get some of the meat juices also pouring out along with it.
The juices that remain in the jug can be used to make a cornflour slurry gravy by following this page.