In a small bowl, combine the paprika, cayenne, thyme, rosemary, oregano and 1 tsp kosher salt. Stir until well combined and set aside.
Place chicken breasts on a cutting board and cover with parchment or saran wrap. Using a meat mallet or the bottom of a skillet, pound chicken until it is a uniform 1/4 inch thickness.
Season both of the chicken breasts all over with 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper. Now, take about 1 teaspoon of the prepared spice mixture and evenly sprinkle on both sides of the chicken breasts (reserving the remaining mixture for later).
Heat oil in a large skillet with sides (I use a 3 qt. Saucier) over medium-high heat. When hot, but not smoking, sear the chicken until golden brown on both sides and cooked through, 3 to 4 minutes a side. Transfer cooked chicken to a cutting board and let rest while you make the pasta.
Reduce heat to medium. Add onion and garlic to the same skillet and saute, stirring, until tender, about 3 minutes. (If your skillet is dry, add an extra tsp of oil.)
Add the pasta, broth and milk. Season with salt and the remaining seasoning blend. Bring the contents in the pot to a gentle simmering (you don't want it to be boiling). Cook, simmering and stirring often until pasta is al dente and liquid is absorbed and creamy, 12 to 15 minutes.
Finish with lemon juice and taste, adjust salt and pepper, as desired. Serve in a bowl and top with sliced chicken, roma tomatoes, green onion and shredded parmesan (optional). Enjoy!