Set the Instant Pot to sauté. Melt the butter. Add in the shallots and cook for 2-3 minutes.
Sear the pork chops for 2-3 minutes on each side.
Turn off the Instant Pot. Pour in the beef broth and Worcestershire sauce. Close the Instant Pot, making sure the valve is set to "sealing". Cook on high pressure for 15 minutes.
Allow pressure to release naturally for around 5 minutes, then manually release.
Remove the pork chops and turn the Instant Pot to sauté. Mix in the cornstarch and sour cream, mixing until the gravy thickens.
Turn off the Instant Pot. Pour the gravy on top of the pork chops.