Melt the butter in a large pot over medium heat. Add the flour and cook for 2 minutes, stir frequently.
Add the milk while stirring with a whisk. Continue adding and stirring until the sauce is smooth.
Add the Worcestershire sauce, 1 teaspoon salt, black pepper, mustard powder, garlic powder, and onion powder. Stir well until incorporated.
Still on medium, let the sauce come to a simmer. This will take approximately 6-8 minutes, stir occasionally. Then lower the heat to medium-low to low as soon as it simmers.
Cook the sauce for 2-3 minutes simmering gently. Stir often, especially when it starts to thicken and do not leave it unattended.
The sauce will thicken as it simmers, do not raise the heat because it will scorch the bottom of the sauce.
Remove the pot from the heat. Stir the sauce a few times and wait until it stops simmering.
Next, add the cheese a handful at a time. Stir until it melts and add another one. Continue adding and stirring until it is melted.
Place the pot back over medium heat. Add the steamed broccoli and macaroni to the cheese sauce. Stir well and place on medium-low to low heat for about 5 minutes to warm through. Do not let it come to a simmer. Take it off the heat.
Taste and add salt if needed. As a reference we added ½ teaspoon to ours. The sauce will thicken as it cools. Serve and enjoy.