Preheat the oven to 425 degrees Fahrenheit.
Trim the broccoli head and separate the florets, then wash them thoroughly and pat them dry.
Place the broccoli florets in a large mixing bowl. Drizzle olive oil, and season with salt and black pepper. Mix so that the oil coats the florets equally.
Spread the broccoli evenly on a parchment-lined baking tray and cook for about 10 to 12 minutes or until they are lightly roasted.
Once done, take the baking tray out of the oven and set the roasted broccoli aside.
While the broccoli is cooking, fill a pot with water and season it with salt. Place it on a stove over high heat. Once the water starts to boil, add penne pasta and cook until al dente.
Drain the water (reserving half a cup for later) and set the pasta aside.
Place a pan over medium heat and add olive oil.
Add chopped onion and sauté until they turn translucent for a minute or two until they turn translucent.
Add minced garlic and cook for a minute or until fragrant.
Add boneless chicken and cook. Season with Italian seasoning, black pepper, and salt to taste.
Once the chicken is cooked through, add roasted broccoli and mix well.
Add cooked pasta and about ¼ cup of pasta water, then incorporate the parmesan cheese and stir gently to that the cheese is just combined.
Drizzle olive oil on top and serve immediately.