While in the oven, I damn near burned my hands off cutting open the rolls, and covering the bottom buns with the horseradish mayo. I realized I had about a cup and a half of beef juice from the sous vide bag – why let it go to waste? I strained it into the pan that the shallot shrooms were cooked in, and cranked the heat. The cheese was starting to melt on the beef, I had to move quick if these sandwiches were going to be perfectly warm at serving time. The pan bubbled, as I poured about a half of a pint of my home brewed Blackberry Porter in with the juices. I salted and peppered and tasted – delicious – now I just needed to thicken it. I got out a rubber coated whisky (because I never use metal in non-stick, no matter how good of a quality non-stick it is) and whisked like crazy as I sprinkled flour into the area I was whisking (to try an avoid lumps – which I did). The cheese was just about to start bubbling on the beef, so I pulled them out and set them next to the rolls to cool off just a little before I assembled. I came back to the sauce and it was thickened perfectly! like thick gravy – and super tasty. I used a spatula to transfer all of the beef piles to the horseradish mayo rolls, and then pulled the pan with the gravy over and put a spoonful onto the inside of the roll tops. I then flipped the roll tops onto the cheese beefy shalloty shroomy piles, and stuck two toothpicks in the east and west hemispheres, and cut them down the middle. I left the toothpicks in, and transferred each piece to my serving platter –