Cook the Pasta and Broccoli
Bring a large pot of salted water to a boil.
Cook the penne pasta according to package instructions until al dente.
Add the broccoli florets to the pot during the last 5 minutes of pasta cooking.
Drain pasta and broccoli in a colander and set aside.
Sauté the Aromatics
Heat olive oil in a large pot over medium heat.
Add diced onion and sauté for 2–3 minutes until softened.
Stir in minced garlic, salt, and black pepper, cooking for another minute.
Make the Creamy Sauce
Sprinkle all-purpose flour over the onion and garlic mixture, stirring constantly. Cook for 1–2 minutes to remove the raw flour taste.
Gradually whisk in whole milk, ensuring no lumps form.
Cook for 2–3 minutes, allowing the sauce to thicken.
Stir in Parmesan cheese until fully melted and the sauce is smooth.
Combine Everything
Add the cooked pasta, broccoli, and diced chicken breasts to the creamy sauce.
Toss gently to ensure everything is evenly coated and heated through.
Serve and Garnish
Transfer to a serving dish and garnish with additional Parmesan cheese if desired.
Serve hot and enjoy!
