01 - Bring a large pot of generously salted water to a rolling boil. Add the pasta and cook according to package directions until al dente. Reserve ½ cup of the starchy pasta water, then drain the pasta and set aside.
02 - While the pasta cooks, pat the chicken breasts dry and season both sides generously with salt, freshly ground black pepper, and Italian seasoning. Heat the olive oil in a large skillet over medium-high heat. Sear the chicken for 5 to 6 minutes per side until a deep golden crust forms and the internal temperature reaches 165°F. Transfer to a plate and let rest for several minutes before slicing thinly against the grain.
03 - Reduce the heat to medium. In the same skillet with the rendered fond, melt the butter. Add the minced garlic and sauté for about 1 minute until fragrant and lightly golden, being careful not to let it brown.
04 - Stir in the sliced sun-dried tomatoes and cook for 1 minute to release their concentrated flavor. Pour in the chicken broth and bring to a gentle simmer, using a wooden spoon to scrape up all the caramelized bits from the bottom of the pan.
05 - Pour in the heavy cream and add the freshly grated Parmesan cheese, stirring constantly until the cheese melts and the sauce is smooth. Let it simmer for 2 to 3 minutes until it thickens enough to coat the back of a spoon. Stir in the crushed red pepper flakes if desired.
06 - Return the sliced chicken to the skillet along with the drained pasta. Toss everything together until evenly coated in the creamy sauce. If the sauce feels too thick, loosen it with a splash of the reserved pasta water. Taste and adjust the salt and pepper. Serve immediately, garnished with fresh basil and additional Parmesan.