Liberally season all sides of the pork roast with salt and pepper. Select the Sauté button to heat up the Instant Pot inner pot.
When the display reads “Hot,” add the butter to the pot. As soon as the butter melts, add the pork roast to the pot and sear it on all sides, approximately 4 minutes per side.
Add the apple juice to the pot and use a wooden spoon to scrape up any brown bits from the bottom of the pot. Add the onion. Press Cancel to turn off the Sauté function.
Secure the lid, ensuring the valve is turned to the Sealing position. Press the Pressure Cook button and set the time to 20 minutes.
When cooking is complete, let the pot sit for another 15 minutes, and then turn the valve to the Venting position to release any remaining pressure.
Remove the lid and transfer the pork to a cutting board. Let the pork rest for 5 minutes, and then cut it into 3/4-inch slices. Top the pork roast with chutney and fresh pomegranate seeds, if using.
Place all the ingredients in the Instant Pot inner pot and combine them with a good stir. Secure the lid, ensuring the valve is turned to the Sealing position. Press the Pressure Cook button and set the time to 10 minutes.
When cooking is complete, turn the valve to the Venting position to release the pressure. Remove the lid, stir, and serve the chutney either hot or cold.