1 marrow
2-3 eggs
Bread crubs
Cheddar

Peel marrow, remove seeds, grate, put in pan, without water, and simmer.
Drain.
Add crumbs, 1 cup and grated cheese. 2-3 eggs into mix
Place in a greased flour dish. Bake at 160C until risen. 

Can be frozen and is even nicer the next day.