Add 2 tbsp butter to the Instant Pot. Using the display panel select the SAUTE function and adjust to MORE or HIGH.
When butter melts, brown the meat on both sides, 2-3 minutes per side. Meat will not be cooked through. Do not crowd the pot–you may have to work in batches. Transfer browned meat to a shallow dish and cover loosely with foil.
Add water to the pot and deglaze by using a wooden spoon to scrape the brown bits from the bottom of the pot.
Put the meat back into to the pot, top with remaining 6 tbsp butter and sprinkle ranch packet over the top.
Turn the pot off by selecting CANCEL, then secure the lid, making sure the vent is closed.
Using the display panel select the MANUAL or PRESSURE COOK function*. Use the +/- keys to program the Instant Pot for 3 minutes and adjust to LOW PRESSURE.
When the time is up, let the pressure naturally release for 5 minutes, then quick-release the remaining pressure.
Carefully remove the meat from the pot to a serving plate and cover loosely with foil.
(Optional) Drop arugula or spinach into the pot and stir, just until wilted.
Serve pork chops on a bed of greens drizzled with remaining sauce.
The MANUAL and PRESSURE COOK buttons are interchangeable.