I recently cooked beef in a pan, and it came out pretty leathery. I came to cooking.SE to find some advice, and found this:
"The cut is important for both techniques. For sauteing, you need a lean cut - fillet, sirloin, or good rump steak. These should be cooked quickly over a high heat" from Cooking beef: how to make it tender? (most of the advice on the page seems to be "high-heat low-time")
My question is for a bit more follow-up on this. Most importantly, how will I know that the beef is cooked well enough to be safe, without it losing its tenderness? Also if it makes any difference, I'm using a non-stick pan (cooking it in olive oil is okay?)