Step 1

Pulse the garlic, scallions, coriander, chipotle chile, cumin, 2 tablespoons salt, and 1 teaspoon pepper in a food processor or mini-chopper to make a thick paste. If the butcher didn't trim the fat cap on the pork shoulder, trim off all but a thin layer of fat. Make deep incisions with a paring knife, at about 2-inch intervals, all over the meat. Rub the garlic and spice mixture into and all over the meat.

Step 2

Combine the lime zest and juice, orange juice, adobo sauce, olive oil, and cinnamon in a nonreactive stainless steel or glass bowl. Add the meat, cover tightly with plastic wrap, making sure the meat is submerged. Refrigerate for at least 8 hours or up 2 days. Bring to room temperature about 1 hour before roasting.

Step 3

Preheat the oven to 450 degrees F. Put the pork, fat-side up, in a large Dutch oven. Roast the meat, uncovered, for 30 minutes. Add the marinade to the pot and cover with the lid. Lower the temperature to 350 degrees F and roast for 2 hours more. Uncover and continue to cook, basting occasionally, until an instant read thermometer inserted into the meat registers 190 degrees F and the meat is a rich burnished brown, 1 1/2 to 2 hours more. Set aside on a cutting board to rest for 20 minutes before slicing.

Step 4

For the sauce: Strain the pan drippings through a fine mesh sieve into a gravy separator and discard all excess fat. In a small saucepan, mix the pan drippings with 1/2 cup water and bring to a vigorous boil. Slice the meat and serve with the pan drippings.