The best mac and cheese of your life!

This is from Mel's Kitchen Cafe, and it's the best mac and cheese I've ever made. My kids are obsessed, and it's super easy. After making it several times I've adjusted the water to what finally worked for me (the first time the noodles weren't cooked all the way because there wasn't enough liquid). Seriously, this stuff is divine. 

4 c. water

1 can evaporated milk

12 oz. (3 c) pasta (this is not a whole box)

*I've made this with macaroni noodles but we all prefer shells!

1 t. cornstarch

1/2 t. dry mustard

1 1/2 c. shredded monterey jack cheese

1 1/2 c. shredded sharp cheddar cheese

2 T. butter

In a skillet, combine water, 1 c. of the evaporated milk, and noodles. Bring to a boil and keep boiling, stirring often, for 9-12 minutes (until pasta is done and most of the liquid has thickened). While it's cooking, pour the rest of the evaporated milk in a bowl and add dry mustard and cornstarch. Stir it all together until combined (use a fork or small whisk). Once noodles are done, pour into skillet. Stir/boil for another minute until all combined and thickened. Turn off heat and add cheese and butter. Season with salt and pepper.