Cut deep slices on the top of the pork roast.

Smash the garlic cloves.

Combine salt, smashed garlic, and oregano.

Rub the salt, garlic, and oregano mixture into the slices.

Squeeze juice from the sour oranges.

Pour the sour orange juice all over the pork roast.

Refrigerate the pork roast for at least 24 hours to marinate.

Preheat oven to 300°F (150°C).

Place the marinated pork in a roasting pan with all the juices.

Cover the roasting pan with foil.

Cook the pork for 1 hour covered with foil.

Remove the foil from the pan.

Continue to cook until the pork roast is tender.