Heat a heavy bottom pan and cook the macaroni in salted boiling water according to the package instruction (little less than 1 minute). Once the pasta is cooked drain the water and keep it aside.
Meanwhile, in a separate pan, steam the broccoli florets for 5 minutes and set aside.
In the same pan add the butter, once the butter is melted add in the flour. Cook for a minute.
Keep the stove on a medium-low flame and add in the whole milk and half and half milk slowly. Whisk continuously to avoid any lump formation. Cook for 3-5 minutes until the sauce turns smooth and thick enough to coat the back of the spatula.
Add the spices; mustard powder, garlic powder, black pepper, paprika, and salt. Mix it well.
Stir in the grated cheddar cheese into the sauce. Once the cheese has completely melted, add the cooked pasta and broccoli florets to it. Mix it until the sauce has coated evenly.
Transfer the broccoli mac and cheese to a bowl and serve hot.