Bone marrow custard is a nutritious dish ideal for a substantial breakfast with sliced fruit, and also pairs nicely with a crisp green salad at lunchtime.
Preheat the oven to 425°F/218 °C
Put the bones in a single layer in a roasting pan and roast for 30 minutes. Remove the pan from the oven and let the bones cool until they are comfortable to handle.
Decrease the oven temperature to 325°F/163 °C and grease six 4-ounce or four 6-ounce ramekins with a bit of butter.
Extract the marrow from the bones with a spoon and drop it into a bowl, discarding the bones. Whisk the eggs and cream into the marrow, then pass the mixture through a fine-mesh sieve set over a bowl to remove any coagulated bits of marrow or lumps of egg. Whisk in the salt, pepper, and parsley.
Pour the mixture into the buttered ramekins and place the ramekins in a large baking dish. Fill the dish with enough hot water to reach halfway up the sides of the ramekins. Bake for 45 minutes, or until the sides of the custards are set but the centers remain a touch wobbly. Serve bone marrow custard warm.