Have u read the book by Ian billinghurst "give ur dog a bone"?
If not get it....really good advice re introducing, I leant mine out a few years ago and never saw it again.
Lamb is what I consider heavy ie very greasy and will lie in the tum for ages, even harry who is used to raw will regurgitate those.
The best starter is a chicken wing, then perhaps a chicken carcass if u can source them.
Be prepared to get friendly with ur local butcher lol