The best mac 'n' cheese you'll ever have

Really.  Honest.  The best.

1 lb elbow macaroni (I prefer Barilla brand; the elbows have a surface roughness that holds sauce well.)
8 Tb butter
8 Tb flour
4 c milk
8 oz shredded sharp cheddar cheese
4 oz shredded asiago cheese
8 oz whole-milk ricotta cheese
1 tsp dry mustard
1 tsp worcestershire sauce
1/8 tsp nutmeg
salt & pepper

Cook the elbow macaroni until just  barely cooked.  Undercooked even.  Drain.  Cool.

Make the sauce.  Melt the butter in a saucepan.  Add the flour and cook a few minutes until you have a nice, uniform roux.  Add the milk, whisking to avoid lumps.  (You can scald the milk if you like.  I'm not convinced it is necessary.)

Cook the sauce until it thickens slightly.  Add the mustard, worcestershire sauce, nutmeg, and salt and pepper to taste.

Pre-heat your oven to 350°F.

Off heat, add the cheddar cheese to the sauce.   Stir well, and let it melt.  It might not melt fully.  It doesn't matter.

Dump the cooked, cooled pasta into a large bowl. Add the ricotta cheese to it and mix it in well. Add the shredded asiago cheese.  Mix well.  Pour in the cheddar cheese sauce.  Mix the whole thing well.  Pour into a greased casserole.  Cover with non-stick foil, place on a sheet pan, and put into the hot oven.  Bake 20 minutes covered.  Remove the cover, and bake an additional 20-25 minutes until bubbly and brown on top.