Preheat the oven to 400 degrees F (200 degrees C). Unroll each sheet of crescent dough sheets (if using crescent rolls, pinch the seams together to form one solid sheet).
Divide sausage roll in half and spread each half evenly into a very thin layer over the dough sheets.
Spread 1 tablespoon mustard over each sausage-topped sheet and top evenly with cheese.
Beginning with the longer side of the dough, roll it securely into a log. If dough has become too soft or warm, freeze it for 10 minutes before slicing.
Slice each roll into 22 (1/2 inch) slices and place on 2 lightly greased, parchment-lined baking sheets.
Bake in the preheated oven until golden brown and toasted on the bottom, 12 to 14 minutes.
