1) Cut the sirloin top across its grain into 1/8-inch thick slices.
2) Dust a mixture of flour and mustard over the sirloin slices.
3) In the saucepan, melt butter. Add in the onion and mushrooms and saute for a few minutes.
4) Mix in the condensed consomme, wine and worcestershire sauce. Cook on simmer for about 15 minutes, till the sauce reaches its desired consistency.
5) Keep stirring in between.
6) Serve the Saucy Sirloin, garnished with chopped parsley leaves.
7) Alongside, serve steamed rice.