Skillet Mac and Cheese from America's Test Kitchen

3 1/2 c. water
1 (12 ox) can evaporated Milk
3 cups elbow macaroni
salt and pepper
1 tsp corn starch
1/2 tsp dry mustard
1/4 tsp hot sauce
2 cups shredded cheddar cheese
2 cups shredded monterey Jack cheese
3 TB butter

Bring 3 1/2 cups water, 1 cup evap milk, macaroni and 1/2 tsp salt to simmer in skillet over high heat, stirring often until Mac is tender. Whisk remaining 1/2 cup evap milk, cornstarch, mustard and tobasco together then stir into skillet. Continue to simmer until thickened, about 1 min.
Remove from heat, stir in chesses one handful at a time--add additional water as needed to adjust sauce consistency. Stir in butter and season with salt and pepper.