6 pound boneless pork shoulder roast
5 cloves garlic, minced (about 2 tablespoons)
2 tablespoons olive oil
1½ tablespoons apple cider vinegar
1 tablespoon fresh lime juice
1½ tablespoons dried oregano
1 teaspoon onion powder
½ teaspoon ground cumin
1 teaspoon chili powder
1½ teaspoons sugar
1½ tablespoons salt
1 teaspoon freshly ground black pepper
2 large onions, sliced

Rinse your roast and pat dry with a paper towel. Make the marinade by mixing together the minced garlic, olive oil, vinegar, lime juice, and all of the dry herbs and spices in a bowl.
Rub the entire roast with the marinade, ensuring that all areas of the roast are completely covered. If you’re using a boneless roast, already tied by the butcher, try to work some of the marinade in the empty cavity where the bone used to be. If you know how to tie your own roast, marinating the meat before tying the roast will ensure the best results. If you’re using a roast with skin, be sure to score the skin with a sharp knife to form a cross-hatch pattern, and rub the marinade into the entire roast. Taking your time marinating a roast properly is the most important step!
Next, cover the roast with plastic wrap and let it marinate overnight for at least 18 hours for the best results.
Take the roast out of the refrigerator, and let it come up to room temperature–about 2 hours.
Preheat the oven to 425F. Cover the bottom of the roasting pan with sliced onions, and add one cup of water.
Cook the roast at 425F for 30 minutes. After 30 minutes, turn the roasting pan 180 degrees, and roast for another 30 minutes. Place a sheet of aluminum foil on top of the roast with the sides exposed if the roast starts to burn
Reduce the heat to 350 degrees and continue cooking for 3 hours, adding about ½ a cup of water every half hour, or as needed. You don’t want to let the bottom of the pan dry out and burn.
For the last half hour, turn the temperature up to 425F if the roast needs more browning.
When the last half hour has elapsed, turn off the oven and leave the roast for another half hour with the oven closed.