Add the pasta, salt, and water to the Instant Pot and attach the lid. Ensure the valve is in the sealing position and cook on high pressure for 4 minutes. When the Instant Pot has finished, release the pressure manually by switching the valve to the venting position.
Remove the pasta to a large bowl. Add the olive oil, cherry tomatoes, and garlic to the instant pot and toss to combine. Place the block of feta in the center and reattach the instant pot lid (make sure your valve is in sealing position again). Cook for an additional 4 minutes on high pressure.
Release the pressure manually and remove the lid. Break up the tomatoes (either using a fork or wooden spoon) and mix in the feta. Add the pasta and toss to combine. Add the basil and enjoy!
Store any leftover pasta in an airtight container in the fridge for up to three days.
Notes
Leftover feta pasta will keep in the refrigerator for 3-4 days, or in the freezer for up to three months.