Bring a pot of water to a boil on the stove top. Add Elbow Macaroni (2 cup), and cook until al dente, about 8-10 minutes.
In a separate pan, over medium heat, melt the Butter (3 1/2 tablespoon). Once melted, pour in Milk (1 1/2 cup) and plain All-Purpose Flour (2 tablespoon). Whisk until flour is completely dissolved. Continue stirring until mixture comes to a boil.
Turn heat down to a simmer, stirring constantly, and cook for 2 minutes. Add Cheddar Cheese (1 1/2 cup), and mix until cheese is fully melted.
Add drained macaroni, and mix until thoroughly combined.