If you follow the recipe as written, it has you strain out the solids after the sauce is made. I skip that step as it would get rid of the onions. The Dijon mustard and little bit of blue cheese gives it an amazing flavor.
I cooked it in the oven this time, but normally I smoke it on the egg. It always gets rave reviews from the family.
No problem. Since I was cooking the Mac and cheese in the oven this time, I used smoked Gruyere and smoked cheddar. Turned out great with a hint of smoky goodness.