Break the pasta in half, set aside.
Turn Instant Pot to saute. Saute the olive oil, lemon zest and garlic for 2 minutes.
Turn saute off and add lemon juice, chicken broth, milk, lemon pepper, 1/4 cup parmesan cheese and pasta. Lay the pasta in the pot in a stack, rather than in rows. This will prevent clumping. Stir.
Put lid on the Instant Pot. Set pressure on high for 8 minutes.
After timer goes off, release the steam with a manual release. Put a heavy cloth over the steam spout and turn the handle to "pressure release".
Once steam is released, unlock the lid. Stir the pasta and liquid for a minute until it is well combined. Add remaining 1/4 cup Parmesan cheese and stir until cheese is melted.
Transfer pasta to serving bowl. Top with remaining 2 Tbs. Parmesan cheese and chopped green onions. Enjoy!