Make the Rub: Whisk the Italian seasoning, garlic powder, onion powder, paprika, salt, and pepper together in a small bowl. Sprinkle the dry rub evenly all over the tenderloin.
Sear the Pork: Turn your Instant Pot onto the sauté setting. Add the olive oil and let it heat up for 1 minute. Sear the pork loin on all sides for 2-3 minutes per side. Remove the pork loin from the pot and set it aside.
Simmer: Add the soy sauce, lemon juice, and chicken broth to the pot. Let it come to a simmer, scraping the bits off the bottom of the pot with a spoon or whisk. Add the trivet (rack) to the pot and place the pork loin on top.
Cook: Secure the lid and set the valve from VENT to SEAL. Cook on high pressure for 5 minutes, then let the pressure release naturally for 10 minutes before quick releasing the rest.
Remove: Carefully remove the pork loin from the Instant Pot and set it aside to rest on a cutting board. Remove the trivet.
Make Gravy: Turn the sauté setting on and let the cooking liquid come to a simmer. Whisk the cornstarch with 2 tbsp water to create a slurry and add it to the pot, while whisking, until thickened. You can mix more slurry if you'd like a thicker consistency.
Taste & Finish: Taste the gravy and season with salt and pepper if needed. Pour the gravy into a boat and cut the tenderloin into 1/2"-1" slices.