Reduce the heat under your skillet to medium.
Add the butter and let it melt. Once melted, add the minced garlic.
Cook the garlic for about 30 seconds to 1 minute, just until fragrant. Be careful not to burn it because garlic can become bitter very quickly.
Pour in the heavy cream and stir gently.
Add the Italian seasoning and black pepper. Let the sauce warm and gently simmer for a few minutes.
Now add the grated Parmesan cheese a little at a time, stirring continuously.
The sauce should begin to thicken and become silky.
If it becomes too thick, add a splash of the reserved pasta water. The starch in the pasta water helps create a smooth sauce while loosening the mixture.
Add the Pasta, Chicken, and Broccoli
Return the cooked chicken to the skillet.
Add the pasta and broccoli, then gently toss everything together.
This is the moment when the dish really comes alive. The pasta becomes coated in the creamy sauce, the broccoli picks up the garlic and Parmesan flavors, and the chicken adds that hearty, savory bite.
If the sauce seems too thick, add more pasta water, a tablespoon or two at a time.
Taste the dish and adjust the seasoning if needed.
You may want a little extra salt, black pepper, or Parmesan depending on your taste.