Step 1: Cook the Pasta and Broccoli
Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions. During the last 3 minutes of cooking, add the broccoli florets to the pot. Drain and set aside.

Step 2: Sauté the Chicken
While the pasta cooks, heat olive oil and butter in a large skillet over medium-high heat. Season the chicken with salt and pepper. Add to the skillet and cook for 5–6 minutes, stirring occasionally, until browned and cooked through. Transfer to a plate.

Step 3: Make the Sauce
In the same skillet, reduce heat to medium and add the garlic. Sauté for 30 seconds. Sprinkle in flour and whisk for 1 minute. Slowly whisk in milk and chicken broth. Add onion powder, Italian seasoning, and red pepper flakes if using. Simmer until thickened, about 3–5 minutes.

Step 4: Add Cheese and Combine
Stir in Parmesan cheese until melted and smooth. Add the cooked pasta, broccoli, and chicken to the pan. Toss to coat everything in the sauce.

Step 5: Taste and Serve
Taste and adjust salt or pepper as needed. Serve hot with extra cheese or a sprinkle of parsley if desired.