Pibil-Style Pork

Ingredients

1 medium onion, quartered through core

4 garlic cloves, peeled

1/3 cup fresh orange juice

1/3 cup fresh lime juice

1/4 cup achiote paste

1 tablespoon red wine vinegar

2 teaspoons coarse kosher salt

1 teaspoon ground black pepper

1 teaspoon ground cumin

1/2 teaspoon dried oregano (preferably Mexican)

1 4 1/2- to 5-pound bone-in pork shoulder roast (Boston butt)