Pork Belly is like a magical fruit. There are several great things we can pull off one cooking pass, but it does take (a very little bit) additional effort.
Look for "pork belly" in the meat section. Seems to run a little higher than butts, probably $5-ish per pound. GENERALLY you won't need like a ton of it, maybe 2-3 people per pound? Kinda depends, see below.
Cracklin' is just one little layer, so you're depending on surface area. a 2# belly piece will make maybe 2-4 people happy with cracklin'
Chashu goes a bit further, like 4 people per pound.
Rub heavily with pork-friendly rub. The cracklin' side is not as thirsty. Get the bottom real well. Lay it skin-up in a greased, shallow tray or glass dish.
~ 1 hour at 300, then ~ 1 hour at 500. Yes seriously. You want it to get real bubbly. My first two tries were not hot enough. 3rd try I was like "well this is h*cked" but it turned out super great. If it's not hot enough it stays pretty leathery...
The cracklin' layer will mostly lift right off the meat. Like, you'll have a hard layer of the good stuff, then a super soft layer of fat, and the rest of the good stuff. Pull 'em apart, it's not rocket surgery.
That cracklin' layer is super good and people will fight over it. Make sure you set some aside before you put down the knife. Eat 'em right now hot, or even let 'em cool down a little and go to town.
The rest is basically TURBO CHASHU. Cut it across the grain into long strips of turbobacon. You can eat 'em straight, crisp 'em on a grill for sandwiches, or just toss 'em into a bowl of ramen.
Please let me know if this survives long enough to be left over.