Cook the pasta: Bring a large pot of salted water to a boil. Cook the bowtie pasta until al dente according to the package directions. Reserve about 1 cup of pasta water before draining.
Prepare the chicken: Cut the chicken breast into small, similar-sized pieces. Season with Italian seasoning, salt, and black pepper.
Brown the chicken: Heat the olive oil in a large skillet over medium-high heat. Add the chicken in a single layer and cook until browned and completely cooked through. Transfer it to a plate.
Cook the garlic: Reduce the skillet to medium heat and add the butter. Stir in the minced garlic and cook briefly until fragrant without letting it brown too much.
Make the Alfredo sauce: Pour in the heavy cream and let it gently heat. Do not let the cream boil aggressively.
Add Parmesan: Reduce the heat and gradually stir in the grated Parmesan until melted and smooth.
Adjust the consistency: Add reserved pasta water a little at a time if the sauce is too thick. Stir after each addition until the sauce becomes creamy and coats the back of a spoon.
Combine everything: Add the drained bowtie pasta and cooked chicken to the skillet. Toss gently until the pasta is evenly coated and the chicken is heated through.
Add broccoli if using: Stir in lightly cooked broccoli with the pasta and chicken. Keep the broccoli slightly tender rather than soft.
Finish the dish: Taste and adjust the salt and black pepper. Add fresh parsley and a little extra Parmesan before serving.
