01 - Cook the pasta according to package instructions in salted boiling water until al dente. Drain and set aside, reserving 1/2 cup of the pasta water.
02 - While the pasta cooks, season the chicken pieces with salt, pepper, and Italian seasoning.
03 - Heat olive oil in a large skillet over medium-high heat. Add chicken and cook until golden and cooked through, about 6–7 minutes. Remove chicken from the skillet and set aside.
04 - In the same skillet, melt the butter over medium heat. Add the minced garlic and sauté for 1 minute until fragrant.
05 - Pour in the chicken broth and heavy cream, stirring to combine. Bring to a gentle simmer.
06 - Add the mozzarella and Parmesan cheeses, stirring continuously until the sauce is smooth and thickened, about 3–4 minutes. Season with salt, pepper, and red pepper flakes if using.
07 - Return the cooked chicken to the skillet, then add the cooked pasta. Toss everything together, adding reserved pasta water a little at a time if the sauce is too thick. Remove from heat and sprinkle with fresh parsley before serving.