Add tomatoes, basil, garlic, balsamic vinegar, salt, and pepper to a small bowl. Mix well to combine. Then add feta cheese and mix again. Set aside and let sit at room temperature for at least 30 minutes, and up to 2 hours.
Using sauté setting – once hot, add oil and chicken (seasoned with garlic salt) to pot. Let cook undisturbed for about five minutes. You kinda want it to stick, so don’t move it around. Once you’ve got some decent color on it, flip the chicken and cook for another 5 minutes or so.
Add onions and give a good mix. Once the onions begin to sweat, use the liquid to scrape up all the brown bits from the bottom. This is why we let the chicken stick, so that flavor could be developed and make its way into the sauce.
Add penne pasta and chicken broth to pot, but DO NOT SITR at this point. Just gently press down so that the pasta is mostly submerged. Lock lid and cook for 3 minutes at high pressure. Once cook time is complete, quick-release pressure. Then gently give a mix.
Pour in cream and parmesan cheese. And again, give a good mix to incorporate completely.
Drain off any liquid from tomatoes, then add most of them to the pasta. Reserve some to add to the top of each bowl. Give one final mix and serve.