Chop the mushrooms and onion/shallot and set aside.
Cut the beef bottom round steak up and set aside.
In a 12 inch frypan use 3 tablespoons of butter and sauté the mushrooms until golden brown, and set aside.
Add 2 tablespoons of butter to the pan and over medium high heat sauté the beef until brown. Remove from heat and set aside.
Add the shalott/onion and sauté for a couple of minutes. Add the balsamic vinaigrette and wine and bring to a boil. Reduce liquid by about 1/4
Remove from heat reintroduce the mushrooms and taste the sauce. If the sauce needs sugar add the sugar now. pour over beef and enjoy!