OOPS!! Boy, I surely screwed up. after reading the responses, I decided what it was. It was flap meat from a large prime rib roast. Some people swear that it's the best part of the roast, especially when prepared medium rare, since it's near the surface it's normally turns out well done. I'll report back later on how the Bourguignon turned out. As suggested in the recipe, I left it in the frig. overnight to let the spices meld.