
Cook the pasta. Boil a large pot of water and salt it well. Add the pasta and cook to al dente according to the package instructions. Reserve about 1/2 cup of the cooking water before draining the pasta.
Meanwhile, prep the chicken. Pat the chicken dry, then slice into bite-size pieces or strips. Season all over with the pepper, dried oregano, and a good dash of salt.
Sear the chicken. In a large pan, heat about 2 tablespoons extra virgin olive oil over medium-high until shimmering. Add the chicken and cook, tossing occasionally until the chicken pieces are cooked through (they should have a delicious golden-brown hue), about 7 to 8 minutes.
Flavor the chicken. Add the garlic and sun-dried tomatoes to the pan with the chicken and stir it around for about 30 seconds or so, then add the grape tomatoes and artichoke hearts. Toss to combine and turn the heat to medium-low.
Make the creamy pasta sauce. In a small bowl, whisk the milk, flour, and Parmesan cheese. Pour the mixture into the pan and add the baby spinach. Add a little bit of the pasta cooking water (just a couple tablespoons or so) and give it a good stir, which releases the starch and makes the sauce creamy.
Finish and serve. Add the pasta and mix to combine. Sprinkle on the parsley and serve.