This is why I will never be a vegetarian. Bone marrow (at least of the bovine variety), when done nicely like the example below from Osteria Stellina in Point Reyes Station, California (http://osteriastellina.com/) taps deep into the collective cave-man (or woman) cortex. Like "beef butter", the slightly unctuous marrow spreads into a flavorful sheen onto whatever lucky delivery vehicle the diner chooses. I chose the supplied bread.
Osteria Stellina served up this tasty example with a simple garnish of garlic, capers, parsley, and lemon zest.