Put pressure cooker on Saute Function. Meanwhile season the pork with salt and pepper. Add oil to pot. Brown both sides of pork. Add sliced onion and remove pork to a plate for the moment.
Saute onion for 3 minutes. Stir occasionally. Stir in apple cider and dijon mustard until combined. Add chicken broth and scrape all browned bits from the bottom of the pot.
Return pork to the pot. Add apple and rosemary. Hit cancel on the screen and then select "Stew" for 15 minutes.
Allow to naturally release 10 minutes then open pot. Slice the pork and serve with the softened apple and onion.