Jamaican jerk chicken recipe

1 medium onion, coarsely chopped 3 medium scallions, chopped 2 Scotch bonnet chiles, chopped 2 garlic cloves, chopped 1 tablespoon five-spice powder 1 tablespoon allspice berries, coarsely ground 1 tablespoon coarsely ground black pepper 1 teaspoon dried thyme, crumbled 1 teaspoon freshly grated nutmeg 1 teaspoon kosher salt