Cook the pasta and broccoli:
Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions. During the last 2-3 minutes of cooking, add the broccoli florets to the boiling water with the pasta. Drain the pasta and broccoli, then set aside.

Cook the chicken:
Season the chicken cubes with salt, pepper, and garlic powder. In a large skillet over medium heat, heat the olive oil or butter. Add the chicken and cook for 6-8 minutes, stirring occasionally, until fully cooked and lightly golden on the edges. Remove the chicken from the skillet and set aside.

Make the Alfredo sauce:
In the same skillet, melt the butter over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant (be careful not to burn it). Slowly pour in the heavy cream, stirring constantly. Bring the mixture to a gentle simmer and cook for 3-4 minutes, allowing it to thicken slightly.

Add Parmesan and seasonings:
Stir in the grated Parmesan cheese and Italian seasoning until the cheese is fully melted and the sauce is smooth. Taste the sauce and season with additional salt and pepper if needed.

Combine everything:
Add the cooked chicken, pasta, and broccoli to the skillet with the Alfredo sauce. Toss everything together until well coated in the sauce and warmed through, about 2-3 minutes.

Serve and garnish:
Transfer the pasta to a serving dish or individual plates. Garnish with chopped parsley and extra Parmesan cheese for a beautiful finishing touch. Serve immediately and enjoy!