Add olive oil and butter to the Instant Pot. Using the display panel select the SAUTE function.
When oil gets hot and butter melts, brown the meat on both sides, 6 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 carrot, shallot and garlic to the pot and saute until shallots begin to brown, 2-3 minutes.
Add wine 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, turning once to coat. Top with thyme sprigs.
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 45 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 serving plate and cover loosely with foil.
Using a wide spoon or a fat separator, skim off most of the fat in the remaining liquid and discard.
Turn the pot off by selecting CANCEL, then select SAUTE. Mix in balsamic vinegar and cook and stir until sauce is reduced by half, about 10 minutes. Discard thyme sprigs.
Serve beef drizzled with sauce.
*The MANUAL and PRESSURE COOK buttons are interchangeable.