Add olive oil to the Instant Pot. Using the display panel select the SAUTE function.
When oil gets hot, add onion to the pot and saute 3 minutes. Add carrot and cook 3 minutes more. Add garlic and tomato paste and cook for 1-2 minutes more.
Add broth and seasonings to the pot and deglaze by using a wooden spoon to scrape the brown bits from the bottom of the pot.
Add tomatoes to the pot and stir. Add meat to the pot, turning once to coat.
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 and program the Instant Pot for 40 minutes.
When the time is up, let the pressure naturally release for 15 minutes, then quick-release the remaining pressure.
Carefully remove the meat from the pot to a cutting board and shred.
In a small bowl, mix together 1/4 cup of pot juices and cornstarch. Stir into the pot until thickened.
Return the meat to to the pot and fold in the cooked pasta.
Serve hot topped with shredded parmesan.