Very fashionable in posh delicatessens and Masterchef-style TV programs, bone marrow is seen as a swanky and avant-garde ingredient that can only be sourced and understood by "Chef types" but, in reality, it is really inexpensive and easy to prepare. It can be frozen in small batches and mixed in to casseroles or grated in with minced beef or other meats to make even juicier burgers.
Ask your butcher for bone marrow and he will, no doubt, present you with some daunting-looking pieces of shin-bone. Don't panic. Just scoop the soft marrow into a food processor using a teaspoon. It is the consistency of chilled lard or butter so it's not difficult to extract.
Squeeze in the juice of half a lemon, add a minced clove of garlic, a good pinch of maldon salt and blitz for around 8 minutes until it is silky smooth and the consistency of whipped cream.
Pass the marrow through a sieve and then add freshly ground black pepper and chopped parsley. Use immediately or freeze.