Chipotle mayonnaise: add all chipotle mayonnaise ingredients to a medium or small bowl and whisk to combine.
Place in a sealed container in the refrigerator and use within a couple of weeks.
Sandwich toasting: slice the roll and toast it lightly.
Set your oven or toaster oven to broil.
After the roll has been toasted, add half of the cheese to each side of the roll and place them on an aluminum foil-lined sheet pan. Add the roast beef and bacon in a sandwich-sized pile directly onto the foil. Place the sheet pan with both the cheese-topped roll and the meat under the broiler and cook for about 4 to 5 minutes until the cheese is very melty, the meat is warmed, and the bacon is crispy
Sandwich assembly: place the warmed meat onto the bottom roll and top with some of the chipotle mayonnaise. Close the sandwich and serve.