A well flavoured cut from the leg which is sold as bone-in or boneless medallion-shaped pieces of meat.
Perfect in a rich tasty casserole as it will thicken up the sauce itself.
For something to slow cook or braise try braising steak or oxtail.
Beef shin contains some gristle and connective tissue and when cooked long and slow the gristle will turn into jelly which gives it the wonderful rich beef flavour. If you buy shin of beef with the bone in you can cook it 'osso buco' style.