Using a strainer, rinse macaroni shells in cold water. Set aside.
Add water and shells to a large pot. Bring to a low simmer over medium heat, stirring constantly. Once it reaches a simmer, add milk and bring back to a simmer.
Reduce heat to medium-low and cook shells through, stirring frequently, approximately 5 minutes. There should still be milk in the pot.
Stir in spices and cheeses over low heat, until cheese is melted. If the macaroni and cheese is too thick, add milk 1 Tbsp at a time until it reaches desired consistency.
Season with salt and pepper to taste.
Serve immediately with a garnish of fresh parsley.
Rinse your pasta first. I know, there is a lot of debate out there about rinsing your pasta. Some people think that rinsing it will mean the sauce won't stick as well. But I think it helps the pasta just have a better texture.
Drop the pasta in the water and stir right away. As soon as you drop your pasta into the water, give it a stir. This stops the pasta from sticking together.
Don't Let the Water Cook Out of the Pot. While the pasta is cooking, make sure you do not let all of the liquid cook out of the pot, you will need it when you add the cheese and spices.
Add More Milk If Needed. Depending on the consistency you like for your mac and cheese, add additional milk in 1 Tbsp increments.
The macaroni & cheese will continue to thicken as it cools, so you can remove while it is still on the slightly runny side.
Sharp cheddar gives a flavorful punch to the One Pot Mac and Cheese.
Ideally avoid pre shredded cheddar cheese, it doesn't melt as well as freshly grated cheese.
You can use any shape pasta you like, but the macaroni really scoops the cheese into its shape!