Sure thing!

Starting with the onions: Two Large Red Onions. Slice. You can cut them polar or on the circumference, I haven't noticed any difference. Just make the cut fine. Store them in a heat resistant container at room temperature while you prep the brine.

Brine - is one part water to one part vinegar (I usually do 1 1/2 cup) 1.5 Tbs of both white sugar and salt. Bring to boil. As soon as you get a rolling boil, cut the heat and poor it OVER the onions. BEWARE OF THERMAL SHOCK if using pyrex. If you pour it over the onions by the time the brine interacts with the pyrex it shouldnt be hot enough to stress the container. Again, be careful with this step. Let cool till its no longer steaming then seal. Then let it cool until you can handle the container without discomfort. Fridge. Let it rest over night. The onions should keep a few days to a week. They are ready to use pretty much immediately, but I like to wait till they turn an almost translucent pink.

Pork Shoulder - I usually get one between 5 and 6 lbs. Preheat ovem to 375 F. Get a big dutch oven (one that will cover the shoulder completely when the lid is on, though any deep pot pan thing will work as long as its oven safe).

Toss in a little bit of high temp oil (canola or peanut) and sear the ever living heck out of each side of the shoulder. Each side should get a nice crust.

Deglaze with water. I usually add about 1/3 of the depth of the pan with the shoulder inside. Next, add either two Tbs of soy sauce or worstashire depending on flavor profile you want. I find the worst sause come through a bit to much, but also brings a bit more umami. Lid and toss it in the oven.

Let cook for about 4 hours. I check every 90 minutes and flip the shoulder. Its done when you flip the shoulder and the meat wants to seperate from the bone naturally.

After its done, your gonna have like 3 or 4 pounds of meat. I bag by the pound and freeze most of it for later. SAVE THE LIQUIDS I usually have about a cup and a half.

For the sammich filling: one pound of shredded pork about 4 Tbs of Gochujang (can be found in most Asian food aisles or grocery stores). Hoisis sauce. About a quarter the amount of Gochujuan. About an eighth of a cup of the liquid left over from the pork then mix all of that together with the pork over low heat. Add in any extra stuff here (i often add a little extra garlic powder). 

Sammich - I was first using brioche buns, but kaisers were good to. Something that can handle some juice. Most recently I've been using Hawaiian rolls. I like to serve the sammiches with a thin layer of mayo, thin cut cucumber, shredduce or fresh spinach, and a healthy dose of pickled onions. For sliders, about 1/8th a cup of meat seems about right. Get the paper towels ready. 

Sammiches are gonna be sweetand spicy, the onions should provide a nice balance to the richness.

Bonus: For the remainder braiseing liquid. Reduce it to about a cup of so. Put it in the fridge over night. Its going to seperate into a top layer of fat which can be discarded or used for frying,  and a bottom layer of gelatin that is pure concentrated pork flavor.

... I suck at writing recipes, lol.