Bone marrow has been a part of the European diet since medieval times. Early recipes show that marrow was among the ingredients for sweet/savory treats and was also a stand-alone dish believed to have medicinal properties. Tiny silver spoons used to extract cooked marrow from the bones were part of every well-stocked kitchen. It is said that Queen Elizabeth ate bone marrow every day, and she lived a long life indeed!
If you think this dish is only for the adventurous, think again. Though not something to eat every day, marrow, bone marrow, which is about 65% unsaturated fat and is packed with protein and minerals, is certainly something to enjoy sporadically.
So how do you go about handling these bones? If you are lucky to have a good butcher, you can ask him to cut the bones horizontally, making a sort of “boat." Otherwise, you can purchase “beef soup bones” that are cut crosswise. First, soak your bones in a bowl of salted water for 12 to 24 hours. This will help remove any blood they may have. After soaking, drain the water and dry them well. Place them in a sturdy roasting pan and bake in a very hot oven for about 25 minutes.
Roasted bone marrow is a highly prized dish in all of Mexico. Beef marrow is delicious, tasting like beefy, warm butter. When spread on a freshly made corn tortilla, a sprinkling of salt is all it needs. For an extra layer of flavor, add a spoonful of your favorite salsa. (PuristS like me can eat these tacos only with salt. A crunchy salt like Maldon or Fleur de Sel is a must here.) Believe me, there is nothing quite like it.