Break off the tough ends and peel the lower part of the asparagus, parboil in salted water and cut into quarters lengthwise.
Spread beef slices on a board, distribute asparagus pieces evenly on the beef, and roll beef around asparagus as a core. Heat oil in a frying pan and brown the rolls and remove from the pan.
Combine all sauce ingredients in the frying pan and cook down. Return the beef rolls to the pan and shake to coat evenly.
To serve - cut rolls into 0.5 inch pieces and arrange in a serving dish. Serve with mustard.