1 tablespoon extra-virgin olive oil
3 large onions, thinly sliced
1/3 cup raw cane sugar, such as Demerara or turbinado
4 cloves garlic, minced
1 teaspoon dried oregano
1 teaspoon freshly ground pepper
1/2 teaspoon salt
1/3 cup cider vinegar
1 cup chili sauce (I used a southwest red chili sauce from Whole foods)
4-5 tsp minced chipotle chile in adobo sauce (I increased this substantially from the original recipe)
3 pounds boneless pork shoulder or blade (butt) roast, trimmed
1. Heat oil in a large skillet over medium-high heat. Add onions and cook, stirring occasionally, until they begin to soften, 3 to 6 minutes. Add sugar and continue to cook, stirring constantly, until the onions are golden brown, 6 to 8 minutes more. Add garlic, oregano, pepper, and salt and cook, stirring, for 1 minute. Add vinegar and bring to a boil. Cook until mostly evaporated, 30 seconds to 1 minute. Remove from the heat and stir in chili sauce and chipotle to taste.
2. Place pork in a 4-quart (or larger) slow cooker and cover with the sauce. Cover and cook until the pork is almost falling apart, about 4 hours on High or 8 hours on Low.
3. Transfer the pork to a cutting board and shred using two forks. Stir back into the sauce.
(Can be made ahead and frozen as well)