The most tender portion of a chicken is probably the tenderloin which is the sort of a breast within the breast. Turn over a chicken breast so it is skin side down and the loose portion running down the middle of it is the tenderloin. Its tenderness is - of course - really down to how one cooks it.
No, the oyster is down at the chicken's bottom, so to speak, and you can "access" it (or them, I should say, as there is one on each side) most easily after the breast meat has been stripped off. It's very hard to describe without the benefit of a chicken to demonstrate on, but you kind of have to hook your fingers round the back of the wishbone and you will find two nuggets of the most delicious, tender meat.
yep Ravenhair, that's where I found it. And I am going to keep it a secret from those I love so I get both bits! I think the part Rekstout means is the supreme?