forever roasted pork

4 pounds pork shoulder, butt end, boneless (have your butcher bone it for you if you're not sure of your butchering skills)
2 T extra-virgin olive oil, plus more for drizzling
2 medium onions, thinly sliced
1½ t finely chopped fresh sage leaves
gray salt and freshly ground black pepper
about ¼ c fennel spice, recipe follows

bring pork to room temperature by removing it from refrigerator 1 to 2 hours before cooking. preheat the oven to 275°F. heat the olive oil in a large skillet over medium heat until hot. add the onions, cover pan, reduce the heat to medium-low and cook until light brown. be patient, and don't turn up the heat. add the sage and season with salt and pepper. cook until the onions cease throwing off water, about 3 minutes. remove from heat, allow to cool on plate.

open up the pork roast and spread a good amount of the fennel spice and add the onions directly to the middle of the roast. fold the roast back over the onions and tie closed with kitchen string (actually, i used something called food loops. they're silicone, and don't take the crust with them when removed) season well all over with the remaining fennel spice.

arrange the meat in the roasting pan, drizzle with more olive oil and cook until the meat is very tender, about 8 hours. it is ready when it pulls away easily if picked at with a pair of tongs. it is often easiest to cook the meat overnight, or put it in the oven in the morning and let it cook all day. it does not need to be attended. you'll want to, because it will smell so good you won't be able to keep your face out of it, but it really requires no more work at this point.

fennel spice rub:
1 c fennel seeds
3 T coriander seeds
2 T white peppercorns
3 T kosher salt

put the fennel seeds, coriander seeds, and peppercorns in a heavy pan over medium heat. watch carefully, tossing frequently so the seeds toast evenly. when light brown and fragrant, pour the seeds onto a plate to cool. they must be cool before grinding, or they will gum up the blades if you use a coffee grinder. if you're truly patient though, you could use a mortar and pestle.

pour the seeds into the coffee grinder and add the salt. grind to a fine powder, shaking the grinder occasionally to redistribute the seeds. store in a tightly sealed glass jar in a cool, dry place, or freeze.
yield: about 1¼ cups