I have tried a ton of mac and cheese recipes. Even Alton Brown's recipe didn't quite do it for me. This is my favorite so far. I got it from my friend Jonda at Verite. I love it because the cheese sauce is done in the same amount of time it takes to boil the noodles. I have learned to measure the milk and grate the cheese before starting though.
1/4 c butter
1/4 c Flour
1/4 teaspoon ground mustard (I usually add more)
1/2 teaspoon salt
1/4 teaspoon pepper (I add more. I like pepper)
1/4 teaspoon Worcestershire sauce (I usually just add a splash and whatever goes in goes in.)
2 cups milk
2 cups sharp cheddar or blend of cheeses
Melt butter over low heat. Stir in flour, salt, pepper, mustard and Worcestershire sauce. Cook over low heat until smooth and bubbly (mine is usually slightly browned too). Remove from heat (or not. I usually don't). Stir in a small amount of milk and whisk until smooth, then stir in a little more and a little more. Go slow with the milk. It makes a difference in the smoothness of the sauce later. Heat to boiling, stirring constantly (or at least frequently). Keep stirring/boiling for about a minute. Remove from heat. Wait a minute so the milk cools some, otherwise the cheese will break. Add cheese slowly so it all melts.
Add 2 cups (about half a pound) cooked macaroni to cheese sauce. Pour into casserole dish and top with bread crumbs. Bake 20-25 minutes at 350 or until bubbly and browned. (I baked mine for about 15 minutes, then broiled the last minute or so to get a good brown top. It was already pretty hot anyway and this was just the right amount of time to thicken up a bit more.)
Now, I've only made this recipe once baked. Usually I make it stovetop. For that, I halve the recipe- so 2 T butter, 2 T flour, and 1 cup milk. I usually leave the seasonings the same and cheese I add to taste. Cook as directed, then add more milk until it is the right consistency for stovetop mac and cheese (however loose or thick you like it.) Dress the macaroni and serve. I still usually use 1/2 pound of pasta, but the kids actually really like this, so they eat a lot.
Now, whatever you do, don't do like I did the only time I baked it. I asked Alann for a box of macaroni from the basement. He tossed up a box I did not recognize. I think it got left behind from my mother-in-law when she moved. When I cooked it, it tasted VERY strongly of old wheat. I was hoping the cheese would cover it up. Nope. I also extremely oversalted the pasta water, so not only was it really old, but really salty too. So it ended up being rather gross. The cheese sauce is good, the technique is good. Just don't use really salty old pasta.