The Very Best Mac and Cheese

This is the really the best Mac and Cheese.  It causes my daughter to swoon and follow me around the kitchen, and my son to declare me "The Very Best Cooker in the World".

Many Mac and Cheese recipes depend on a cheese sauce made from a simple roux.  Roux may be great, but I think it yields a cheese sauce that is rather grainy, almost doughy, and not smooth.  This recipe is simple.  It uses corn starch as a thickener, which is smoother, less fattening, and easier.  The real secret to amazing Mac and Cheese, is amazing cheese.  Hands down, amazing aged cheddar is going to be way better, but this recipe works well with regular store brand cheese (which is what we usually use).  Also, I love to plan this meal for the day before I go grocery shopping, and I also try to just keep the ingredients on hand because they do not spoil quickly, which means I don't have to worry that I didn't get to it when I planned.  

Yield: 9x9 dish
Ingredients:
2 cups uncooked elbow macaroni (approx 1/2 lb)
3 cups grated cheese (mix 2/3 sharp cheddar, 1/3 Parmesan)
1 cup sour cream
1 tsp Dijon mustard (more if you want)
1 tbsp corn starch

Instructions:
Preheat the oven to 400 degrees.  Cook the noodles, as usual, drain and do not rinse.  They will stick to the sauce better.

Mix the sour cream with the Dijon mustard in a sauce pan.  Put on medium to low heat, and start to melt.  Add all the cheese and mix it together. 

Gradually heat the sauce to melt the cheese.  Mix with a spoon.  As the sauce gets more melted, whisk together.

In a little bowl, mix the cornstarch with cold water to make a slurry.  Dump the slurry into the sauce, and whisk the sauce together.

Allow the sauce to get fully melted and bubbly while continuing to stir or whisk it so that it remains smooth.  Mix the noodles into the sauce.  You can stop here if you want, but the next step makes it just that much better.

Pour the Mac and Cheese into the 9x9 baking dish.  Cover with a little more grated cheese. 

Put in the oven until the top is bubbly and browned, approximately 15 minutes.

My son would now announce that you are "The Best Cooker in the World"!

Variations:
I love to mix chopped cauliflower in with the noodles during the last couple minutes that they are cooking, and then they are mixed throughout the noodles in the final dish.  Cauliflower and cheddar cheese are a match made in heaven, but my daughter hates when I mess with her Noodies and Cheese.  You can also add garlic to the mixture, or black pepper--or truly a million things--but this is the basic, unadulterated, perfect Mac and Cheese.
Also, these cheese sauce is amazing with potatoes to make Potatoes Au Gratin (better known as Funeral Potatoes).