Beef Bone Marrow Spread | Grillhouse-Style Appetizer on Toast

Rinse the split bones in ice-cold salted water; the cold water draws out surface blood so it will not leave gray spots after cooking. Scrape bone dust from the cut surfaces with your fingertip. Pat the bones dry and arrange them on a baking sheet with the cut sides facing up.

Roast on the middle rack of an oven preheated to 200°C / 390°F. The marrow is ready when it puffs up, its edges begin to turn golden, and a skewer inserted in the center meets no resistance. A few drops of fat running onto the tray are normal; if a pool starts to form, it has gone too far.

Remove the bones from the oven and wait 1 minute. Then use a narrow spoon to scoop out the marrow in one piece, running from one end of the bone to the other. If you wait too long, the marrow will firm up inside the bone and come out in pieces. Transfer it to a warm bowl.

Rub the very finely chopped red onion with a pinch of salt and squeeze out its liquid. Mash the marrow with the back of a fork until nearly creamy. Mix in the onion, chopped parsley, lemon juice, sumac, Turkish red pepper flakes, salt, and black pepper. The lemon is there not only for flavor but also to cut through the richness of the fat.

Toast the bread slices in a dry skillet or on a grill until crisp on both sides. While the spread is warm, spread it thickly over the slices and serve immediately; once cool, it firms up and is no longer spreadable.