In an Instant Pot insert, place diced chicken, uncooked penne noodles, chicken broth, diced sun-dried tomatoes, 1 tsp. Greek seasoning, 1 tsp. Italian seasoning, 1/4 tsp. red pepper flakes, 2 1/2 tsp. dried basil, and 1/2 tsp. salt.
2. Stir mixture. Place trivet on top of noodles. This is optional but helps with releasing the steam.
3. Secure lid. Set pressure valve to SEALING. Select MANUAL or PRESSURE COOK; cook on high-pressure 5 minutes. Select CANCEL. Set pressure valve to VENTING to quick-release pressure.
4. Remove lid once pressure pin drops. Stir in 1/4 cup milk, freshly grated parmesan cheese, and softened cream cheese.
5. Stir in 3 cups baby spinach, minced garlic, 1 1/2 teaspoons black pepper, and an additional 1 1/2 teaspoons Italian seasoning.
6. Allow pasta to rest 10 minutes to soak up liquid or serve extra creamy.