Sear the meat: Set your Instant Pot to the “Sauté” program and wait for it to heat up. Once the cooking surface is hot, add 1 tbsp olive oil, 18 oz pork shoulder, 1/4 tsp black pepper, 1/2 tsp salt, 1 tsp paprika, 1 tsp ground cumin, 1 tsp dried oregano, and 1 tsp Dijon mustard. Mix to coat the seasonings evenly. Sear the meat for 5 minutes or until golden brown on all sides.
Sauté the aromatics: Add 1 tbsp minced garlic and 2 oz diced white onions to the pot. Stir constantly for about 2 minutes or until translucent.
Slow-cook the meat: Add 1/4 cup orange juice, 1 cup unsalted chicken broth, and 2 tbsp lime juice to the pot. Stir to combine and cover with the lid. Seal the valve knob and set your device to the “Meat Stew” program. Cook for 45 minutes.
Reduce the meat juice: Carefully turn the valve to release the steam before opening the lid. Set your device to the “Sauté” program and cook for 15 minutes or until the meat juice is reduced by half. While you wait, preheat the oven to 375°F.
Caramelize the meat: Remove the pork from the pot and transfer to a baking sheet. Shred the pork using a pair of forks. Pour the remaining meat juice in the pot over the shredded pork. Mix well to distribute the juice evenly. Spread the shredded pork out on the baking sheet. Put in the oven and bake for 10 minutes or until the pork is crispy on the outside.
Make the taco shells: Put 8 corn tortillas on a taco rack, transfer it to the oven, and bake for 3 minutes. (We didn’t have a taco rack so we improvised and turned a cupcake tray upside down to hold our tortillas.)
Assemble the tacos and serve: Divide the carnitas, 5 oz diced mangoes, 0.5 oz sliced jalapeño peppers, 1 oz diced red onions, and 2 tbsp chopped cilantro into 8 taco shells. Transfer the carnitas tacos to a serving platter and serve with our recommended side dish.