Start boiling a pot of salted water for the pasta. We won't cook the pasta until the last few minutes, but we want the water already boiling.

Season the chicken breasts on both sides with kosher salt, pepper, Italian seasoning, and crushed red pepper flakes.

Set a large skillet over medium heat and add one tablespoon of the olive oil. Once hot add the chicken breasts and cook 3 to 4 minutes per side depending on how thin they are.

Remove the chicken from the skillet and set aside. Add the remaining one tablespoon of olive oil to the skillet along with the diced onions and sliced mushrooms. Season with more kosher salt and pepper and cook 4 to 5 minutes.

Add the spinach, garlic, and chicken base (if using) to the skillet and cook 2 to 3 minutes stirring occasionally. Remove the veggies from the skillet and set aside.

Add the butter, heavy cream, kosher salt, pepper, Italian seasoning, and crushed red pepper flakes to the skillet. Bring to a boil and then reduce the heat to simmer for 5 to 6 minutes, stirring a few times. Stir in the parmesan cheese during the last minute.

Check the cook time on the type of pasta that you're using and boil the pasta timed so that everything is ready together.

Slice the chicken and add it into the skillet along with the cooked veggies and cooked pasta.

Stir until combined, taste for seasoning and add more kosher salt, pepper, Italian seasoning, and crushed red pepper flakes if needed.