Cook the pasta according to the package instructions; drain and set aside.
Heat the oil in a large skillet over medium-high heat. Season the chicken with the Italian seasoning and some salt. Add the chicken to the skillet and cook until golden brown, 2 to 3 minutes per side. Remove the chicken to a plate and set aside.
Add the onions and garlic to the same skillet and cook, stirring, for 3 minutes. Add the broth, then scrape the bottom of the skillet to loosen the bits. Cook for another 2 to 3 minutes to let the broth reduce. Add the marinara sauce and red pepper flakes, bring to a simmer and simmer for 10 minutes.
Turn off the heat and add the drained pasta, mozzarella, ricotta, Parmesan and basil. Add the cooked chicken on top. Toss to combine, then add more of the mozzarella, ricotta, Parmesan or basil until the sauce is just how you like it. Serve with a sprinkling of Parmesan and a little basil on top.