Turn on the Instant Pot and press the Sauté function key. Add the onions, olive oil, and salt and cook for 3-4 minutes, stirring a few times, until softened.Add the reset of the ingredients (except for the vegetables used in the second part of cooking) and stir through well. While it might seem like you need more liquid, remember that the meat will release its own juices in the cooking process.Place and lock the lid, making sure the steam release handle is pointing to Sealing. Press the Manual function key, making sure it's set to High Pressure, and adjust the timing to 20 minutes. After three beeps the Instant Pot will begin to build up the pressure and start cooking. Once the cooking finishes, release the pressure naturally for 2-3 minutes before using quick release to let off the rest of the steam. While the lamb is cooking, you can make a quick couscous or rice dish, or prepare some steamed vegetables on the side.Add the vegetables and orange zest and stir through. Place and lock the lid again, and set to Manual, High pressure, for 5 minutes. Once the cooking finishes, leave the Instant Pot to release the pressure naturally for 10-12 minutes, and then use the quick release method to finish it off.Serve with a chosen side and fresh cilantro and scallions as a garnish. A little lime juice is also nice on the side.