I had never heard of this. I had to google it. I thought you were talking about cream of chicken soup until Thrifty mentioned tuna. Sounds interesting. I may have to try it.
Omg - - that sounds like a delicious sandwich. I like everything you mentioned. And then putting those all on some kind of bread -- bread, one of my favorite foods. :)
I'll keep an eye out for Boar's Head, too. I like horseradish mustard but I simply don't eat it that often. This bottle I just bought could last forever (not literally, you know what I mean, ha).
I use Arnold's 12 grain bread and it's delicious. I thought it wouldn't last either, but it's also good on the same sandwich without the roast beef or the same ingredients with sliced chicken or turnkey. I have a bottle of brown mustard that I believe I've had for about five years. Don't ask me why I keep it.
I may have cheated - I used a boxed prepared dinner with that packet of wet cheese sauce. But I added extra dry pasta with the other provided pasta and after mixing in the cheese packet, I then added some extra milk, two packets of tuna (around a total of five ounces; not canned, this tuna was packed in a small amount of water, no draining was necessary) and extra shredded cheddar cheese and mixed it all together and baked it in the oven a bit.
Now I'll to try some of the other ideas in the other answers. :)
I made a brand new batch again tonight!! This time I used a boxed macaroni and cheese again - but this time, I used the boxed kind that you add butter and milk and the cheese is dry, not a "wet cheese in a packet" sauce.
Again, I added the tuna and extra shredded cheese and baked it all a few extra minutes in the oven - - so good! I like it much better with this "dry" kind of prepackaged macaroni and cheese.