Seeking the impossible -- creamy, homemade mac n cheese without artificial cheese-food products

So, last night I needed to make something for dinner, and our fridge was a little empty. :-) Hey, I need to go grocery shopping…. I know it!

Fortunately, I had a handy package of cheddar cheese and a box of macaroni. Yum! Time for dinner.

I finely minced a half of a sweet onion and sautéed it in some olive oil until extremely softened. Then I added a little butter, then flour…let the flour toast away. And then added the milk of course. After a little love and care, my white sauce was ready, then came the cheese. Yummo! Salt, pepper and a dash of hot sauce -- this mac and cheese was tasty and simple, the way it was supposed to be.

My only complaint? I really want smooth and creamy sauce without the grainy strands, and without having to make my mac and cheese with artificial cheese products. :-)

Over the years, I've collected recipes that claim to create smooth and creamy cheese sauce. Often, these recipes require 3 to 6 hard-to-find-in-Lansing cheeses. Then, when I'm ambitious enough to actually make the huge $$$ investment and try the recipe, the results end up OK, but not really smooth and creamy.

I think I was misled by the blue Kraft mac n cheese boxed creations of childhood. There musn't be a way to really create smooth mac n cheese -- at least not without the wonders of science and handy cheese-like (but not really cheese) products.

Any suggestions or ideas? :-)