Wash the pork in cold water and dry well with a paper towel. Cut the pork in 5-6 sections.
Season the pork with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Rub well.
Turn on the Instant Pot to "Sauté" setting then adjust it to "High" and add 1 tablespoon vegetable oil.
Place about 2-3 pork pieces into the pot and cook until browned on all sides for about 5 minutes. Set aside.
Repeat the process (without additional oil) to the remaining pork. Transfer the pork to a plate and set aside.
Add chopped onion into the pot and stir until translucent, then add garlic, oregano and cumin. Keep stirring for 30 seconds.
Add orange juice, broth, 1 ½ teaspoon kosher salt, 1/2 black pepper, and 1 bay leaf. Keep scraping the pot until no more browned bits are at the bottom to prevent burning.
Put the seared pork back inside the pot. Turn off the "Sauté" setting. Use a big spoon to pour juice over all of the pork.
Place the lid and ensure the valve is in the “Sealing” position. Select "Meat" then press "Pressure" until you see the "High Pressure" light on then adjust to 35 minutes. Once Its cooked, allow the cooker to cool down naturally for about 15 minutes before you open the lid.
Remove the meat from the Instant Pot and let cool slightly before pulling apart with a fork.
Turn on the "Sauté" setting and bring the juice to a boil, then continue cooking to reduce the broth for about 1 minute.
Option 1: You can enjoy the meat immediately after pressure cooking without searing. OR
Option 2: Broiler. Turn on the broiler to High, layer some shredded pork on a baking sheet and cook for about 4-5 minutes, then take it out from the oven and pour in about 1/3 juice all over the meat. Put it back the oven and cook for at least 5 minutes or until crisp on the edges but still tender. OR
Option 3: Skillet. In a large skillet over hight heat, add one tablespoon oil and cook the shredded meat, undisturbed, until underside is well browned, about 4-5 minutes. Add some juice and continue cooking and tossing occasionally, until some of the edges are caramelized until you reach the desired crispiness and flavor. Make sure to keep the meat tender and do not burn.Remove pork from the skillet and repeat this process in multiple batches (about 3-4 total).