>Beef and chicken don't toughen when you overcook them.?
>Since when?

What I mean to ask is there are certain situations when you can cook
meat for a long time, like stewing beef or pot roast, and it retains
its tenderness, or becomes even more tender. In which situations is
cooking meat for a long time a good thing vs. a bad thing? In my mind,
I was not thinking of steak, but I should have been more clear. Thank
you for so eloquently pointing that out to me.

-Luiza