Creamy Skillet Mac 'n' Cheese

Source: Mel's Kitchen Cafe

Ingredients:
3 1/2 cups water, plus extra if needed
1 (12-ounce) can evaporated milk
12 ounces (about 3 cups) elbow macaroni (I have been successful using a full 16 oz package of shell pasta without changing any sauce ingredients)
1/2 teaspoon salt
1 teaspoon cornstarch
1/2 teaspoon dry mustard (I use ~1 teaspoon regular mustard)
1/4 teaspoon hot sauce (doesn't make it hot - just kind of an interesting addition and ups the flavor)
6 ounces cheddar cheese, shredded (1 1/2 cups)
6 ounces Monterey Jack cheese, shredded (1 1/2 cups) (I only had cheddar, so that's what I used, but next time I'd like to try some jack; updated to add the montery jack is so creamy and smooth - I love it and always buy it especially for this dish now)
2 tablespoons butter, cut into small chunks (updated to add: I usually just skip the butter - I don't miss it at all)
Ground black pepper to taste

Directions:
Bring 3 1/2 cups water, 1 cup of the evaporated milk, the macaroni, and 1/2 teaspoon salt to a simmer in a 12-inch nonstick skillet over high heat (I don't have a skillet that big, so I just used my large saucepan - worked great.  Also, watch out on the high heat thing - mine boiled over because it was too high and I ended up "vigorously simmering" at medium instead). Cook at a vigorous simmer, stirring often, until the macaroni is tender and the liquid has thickened, 9 to 12 minutes.

Whisk the remaining 1/2 cup evaporated milk, the cornstarch, mustard and hot sauce together in a small bowl, then stir into the skillet. Continue to simmer slightly thickened, about 1 minute.

Off the heat, stir in the cheddar and Monterey Jack, one handful at a time, adding water as needed to adjust the consistency of the sauce (I didn’t need any additional water when I made it). Stir in the butter and season with salt and pepper to taste. Serve immediately.

Ham and Pea Variation: Follow the recipe, adding 4 ounces deli-style baked ham, diced medium, and 1/2 cup frozen peas to the skillet with the cornstarch mixture in step 2.

Notes:
I had a hankering for some good old fashioned mac 'n' cheese the other day.  I get this hankering about once a year.  Last time I had it, I decided to try a recipe that was getting rave reviews on pinterest and elsewhere in the internet.  It was not my fave.  In fact, it was one of my worse pinterest recipe experiences.  #pinterestfail and all that.  So when the craving for mac came this year, I went to my most trusted recipe source (aside from my own family recipes, of course) - good ol' Mel.  I was slightly skeptical since this recipe had me boiling the noodles in the milk just like the other one did.  But I trusted Mel and gave it a go.  She didn't let me down.  This was super delish.  I didn't think ahead enough to make the ham and pea variation, but I did serve peas on the side, which ended up mixed into my mac, and I must say it was a delight.  I may decide to make some mac more often than annually with this recipe in my arsenal.