Rinse pork in cold water and pat dry. With a paring knife, stab 1-inch slits all over the pork, top and bottom.

In a food processor (or by hand if you have a pilón!), blend all the garlic, olive oil, black pepper and oregano until smooth. Fill each slit in the pork with about a teaspoon of the garlic paste. Sprinkle all sides of the roast with the adobo and sazón (if using) and rub pork with the spices. Place in a roasting pan that has sides at least 2 inches deep, cover with foil and refrigerate for 2 days.

When ready to cook, preheat oven to 350°F. Leave the roast covered with foil and bake for 4-5 hours, approximately 30-45 minutes per pound. Pork should read 180°F on an internal thermometer and shred easily with a fork.

Uncover roast and bake for 15-20 minutes to crisp up the fat, or broil at 500°F for 10 minutes, watching carefully not to burn.