Andy is correct (He's correct 99.9% of the time. The guy just knows his stuff

). Sirloin tip is a fairly lean cut of meat and doesn't make very good steak or stir-fry. It has great flavor but is well exercised and is therefore fairly tough. Sirloin tip is best used in stews or in recipes that use moist and slow cooking techniques. It would be great, for instance, if cut into cubes, seared, and placed in a pressure cooker along with a sliced onion, and a half-tsp. of salt, with a couple cups of water or broth, then cooked at 15 lbs. of pressure for 30 minutes. Remove the pressure as directed by the instructions, then remove the cover. While the beef is cooking, bring a seperate pot of water to boil and cook a batch of egg noodles until they are al-dente. Drain the noodles and set aside. Thicken the liquid from the pressure cooker with either a roux, or a cornstarch slurry, and pour over the noodles. Some people will add a bergundy wine to this recipe. I don't care for the flavor of wine myself.
You can also add saute'd mushrooms to this dish and sprinkle some freshly grated parmesano regiano over the top, or it's also great just with some cracked black pepper.
Sirloin tip is a meat that should be braised or cooked in a pressure cooker, and used with a sauce or gravy.
Oh, and this dish can also be made in a slow oven, in a covered roaster, or in a slow cooker. It just takes several hours rather than thirty minutes as it does in a pressure cooker.
Seeeeeeya; Goodweed of the North