Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in penne and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through but is still firm to the bite, about 11 minutes. Drain well in a colander set in the sink.
Dip chicken breasts into the beaten egg whites.
Press chicken into Parmesan cheese in shallow bowl to coat both sides.
Gently toss between your hands so any cheese that hasn't stuck can fall away. Place the chicken on prepared baking sheet.
Bake chicken breasts in the preheated oven until no longer pink in the center and the juices run clear, about 18 minutes. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).
Meanwhile, heat Alfredo sauce, diced tomatoes, tomato sauce, and red pepper flakes in a large saucepan over low heat. Allow to simmer while you finish the remaining steps.
Heat a large skillet over medium high heat; cook and stir mushrooms and spinach until mushrooms are tender, about 5 minutes.
Stir vegetables into the sauce.
Place the penne pasta into a serving bowl; slice chicken breasts and arrange over the pasta.
Pour sauce over the pasta and chicken, and sprinkle remaining 1 cup Parmesan cheese on top.