Add the oil and ghee to the Instant Pot, hit Sauté, and Adjust so it’s on the More or High setting.
Once the oil’s bubbling and the ghee’s melted (about 3 minutes), add the shallot and mushrooms.
Sauté for 5 minutes, or until the mushrooms soften and begin to brown.
Add the garlic and sauté for 1 minute (or just add the garlic in the next step with the balsamic).
Pour in the balsamic vinegar and Worcestershire (if using) and deglaze the bottom of the pot.
Simmer for 3 minutes.
Add the broth, oregano, seasoned salt and stir.
Add pasta but do not stir. Just lightly submerge in the broth with a mixing spoon.
Secure the lid, move the valve to the sealing position, hit Keep Warm/Cancel, and then hit Manual or Pressure Cook on High Pressure for 5 minutes.
Quick release when done.
Add the yogurt and stir until melted and creamy.
Let rest for 3–5 minutes to slightly cool and thicken.
Serve as is, or top with a drizzle of truffle oil and/or balsamic glaze.
