From the New Century German Cookbook

 

1/4 onion - minced
2 tablespoons butter
1 cup chopped portobello mushrooms
1/2 cup red wine
brown gravy

Saute onions in butter until very tender. Add mushrooms and saute additional 2- 3 minutes. Add gravy and wine, simmer and reduce by half. Serve over beef, rice, potatoes, or noodles.