This is a Sirloin Tip roast, which extends off of the sirloin into the rear leg (or the round). It's a fairly lean cut with a really good beefy flavor.
If you're familiar with venison cuts this is what some call a football roast from a deer or elk. Here are a few more options:
1) There is a way to cook them Hot & Fast: Cut it into 1 1/2" cubes for traditional sirloin tips. Marinate them, load them on skewers and flame broil over a SUPER HOT grill to a med-rare. Let them rest for a good ten minutes tented with foil. Excellent done this way!
2) Roast it to med-rare, let rest and slice thin for roast beef sammies.
3) If you want some awesome tasting burgers, this cut makes most excellent burger meat (ground round).
We do expect to see some pics, whichever way you go!