Adjust the oven rack to the lower-middle position and heat the oven to 300 degrees.
Heat oil in a Dutch oven over medium heat until shimmering.
Add the onion and cook until lightly browned, 4 to 6 minutes.
Add the garlic, cumin, oregano, allspice, and cinnamon and cook until fragrant, about 30 seconds.
Stir in the tomato paste and cook, stirring constantly, until the paste begins to darken, about 45 seconds.
Stir in the water, orange juice concentrate, 2 tablespoons of vinegar, Worcestershire, bay leaves, 2 teaspoons of salt, and 1 of teaspoon pepper, scraping up any browned bits.
Add the pork and bring to a boil.
Transfer to the oven, uncovered, and cook until the pork is tender, about 2 hours, stirring once halfway through cooking.