For my new recipe last week (yikes, I'm bad at this!) I tried "Steak Tips with Peppered Mushroom Sauce" from the blog Elizabeth's Edible Experience. The recipe was originally from Cooking Light magazine (so pretty healthy too) and it turned out really well. I used chicken instead of beef, since we don't eat a lot of red meat and that worked too. I'm sure it would have been heartier with the steak, but the portabello mushrooms really beefed it up (ha!).
Recipe here. Mine turned out a little runnier than the recipe because I will forever suck at thickening sauces with flour/cornstarch, but it was still good. We were actually able to use the leftover sauce as a gravy for a side of brown rice a couple nights later.