This has had me puzzled since I arrived in the US. In general, "stuff" is better in the US than the UK. There's more of it, more choice, and so on. And so apart from a few things like Radio 4, the US tends to beat the UK in material (I'm saying nothing here about the other things in life) things.
But not when it comes to filleting a chicken.
In the UK, when you buy chicken breasts, you can get just chicken. If you really want skin, you can have that too, but in general it's just pure chicken. But in the US, there's still a weird white tendon thing attached to the breast.
In the photograph, the two on the right show you what I mean. I've removed the tendon from the one on the left (I'm making fajitas), but in the UK that's just how they come, straight out the shrink wrap.
What is the tendon thing? It's a pain. And, more to the point, why don't US chicken chopper uppers remove it?
Point to the UK.