To make roasted bone marrow, bake 3-inch segments of beef bones for 15 minutes at 450 degrees Fahrenheit, spread the marrow on toast, and top the toast with parsley salad. To make bone broth, boil the bone segments in water and vinegar for at least 8 hours.
Obtain beef marrow bones that are roughly 3 inches in size, and bake the bones for 15 minutes at 450 degrees Fahrenheit. Scoop the marrow out of the bones, spread it on toast with a small amount of salt, and top the toast with parsley salad. To make parsley salad, mix 1 bunch of chopped flat-leaf parsley, 2 thinly sliced shallots and 2 tablespoons of capers in a bowl. In a separate bowl, whisk 1 1/2 tablespoons of fresh lemon juice with 3 tablespoons of olive oil. Combine the olive oil mixture with the parsley mixture, and serve.
To make beef marrow broth, boil 3-inch segments of beef bones in water with 2 tablespoons of apple cider vinegar. Allow the bones to simmer for at least 8 hours, skimming the foam off the top of the broth as needed. Remove the remaining marrow from the center of the bones, and discard the leftover bones. Vegetables, such as carrots and celery, can be added during the last two hours of cooking to enhance the flavor of the broth.