Note on Cooking Time: the pork roast timing can vary depending on size, whether or not there’s a bone, the time the oven door is open, and the accuracy of your oven. Allow extra time if planning for an event.

The Pork Roast:

Trim the fat cap on the roast down to about 1/3 of an inch. With a large, sharp knife, poke slits into the roast about 1/2 to 3/4 inch deep. Place the pork in a casserole lined with plastic wrap, with the plastic wrap overlapping generously at the sides and ends.

The Mojo:

For the mojo, combine the orange juice, mango juice, lemon juice, lime juice, and oil. Add the minced garlic, oregano, salt, and pepper. Mix well until the salt is dissolved. This makes about 2 cups.

The Pork Roast:

Pour half of the Mojo over the pork (about a cup) and, using clean hands, rub all over the roast, turning as needed; try to get some of the garlic into the slits as you work. Pull plastic wrap up tightly around the pork. Marinate for a minimum of 2 hours and up to 24 hours. Reserve the remaining mojo in a covered container in the fridge.

When ready to cook, preheat the oven to 300°F. Remove the pork from the marinade and the plastic wrap, reserving the marinade. On a large sheet tray with a rim, add a double layer of heavy-duty aluminum foil, enough to fold over the roast and crimp while allowing for extra room. Place the pork roast in the center, drizzle with the marinade, and crimp, leaving a generous amount of space all around the roast.

Roast for about 3 hours. Turn oven temperature up to 325 degrees F.  Uncover the roast and continue to cook, basting every 15 minutes, for another 2 1/2 to 3 1/2 hours or until the pork is very tender and shows no resistance when a fork is placed in the pork and turned.

Allow pork to rest, tented lightly with foil, until cool enough to handle. Remove the pork from the juices, shred the pork with two forks, and set aside. There should be about 2 cups of juices, and about half will be fat; defat as you wish. Combine the juices with the Mojo previously reserved in the fridge. Drizzle some into the pork and toss. Set aside any leftover Mojo mixture for serving.

Once the Oven Is Turned up to 325 Degrees F.:

Make Garlic Aioli:

While the pork is uncovered, slice the bottom off the garlic bulb, turn it over, and place it cut side up on a piece of foil large enough to later pull up the foil and seal over the garlic, about five inches square.

Pull the edges of the foil up to form a small cup. Drizzle a little olive oil over the top, crimp, and bake in the oven (alongside the pork) for about 35 to 40 minutes or until the garlic is soft.

Squeeze the pulp out of the garlic and mash the garlic into a paste. In a small bowl, combine the garlic paste with mayonnaise, olive oil, lime juice, and pickle relish. Stir until blended. Place in a serving bowl if desired. Refrigerate until ready to serve.

Make Caramelized Onions:

Peel and vertically slice the onions into 1/2 inch strips. Add to a large oven-safe skillet (with a lid) along with the oil and butter. Sprinkle with salt and sugar. Cover and place in the oven once the temperature has been raised.

Cook for 15 minutes, then stir. Add the lid and continue to stir every now and then until onions have softened, about an hour, although this can vary. Once softened, take the lid off and allow to brown, stirring every 15 minutes golden brown. Remove and set aside for serving.

Assembly:

Cut an 8-inch-long piece of baguette or use a roll per person. Slice it in half, lengthwise. Spread garlic aioli on both pieces of bread, and lightly broil until the mayonnaise starts to bubble and puff. Remove from the oven.

Layer the pork, onions, pickled jalapeños, and cilantro on one side of the bread. Add a little more of the aioli on the top piece, place it on the sandwich, and serve. Set out the remaining Mojo for those who wish to drizzle on the sandwich.