Roasted Bone Marrow Recipe

Soak and preheat

If bones are bloody or very fresh, soak marrow bones in cold salted water (2 cups water + 1 tsp salt) for 2–4 hours in the refrigerator, changing water once to remove blood. This step reduces bloodiness and yields a cleaner flavor. Preheat oven to 450°F (230°C).

Prepare bones

Remove bones from water and pat dry thoroughly with paper towels. Stand bones upright in a rimmed baking sheet or roasting pan so marrow is exposed on top; if necessary, stabilize with crumpled foil. Season marrow lightly with 1½ tsp of the fine sea salt and 1/2 tsp of freshly ground black pepper, distributing evenly among bones.

Roast marrow

Roast bones in the preheated oven for 15–20 minutes, until the marrow is soft and just starting to separate from the bone but not melted away — it should wobble but retain shape. Rotate pan once halfway through for even browning. Remove from oven and let rest 2 minutes.

While bones roast, prepare the parsley-lemon garnish: finely chop parsley and zest the lemon. Combine chopped parsley with remaining 1/2 tsp salt and remaining 1/2 tsp black pepper and set aside.

Cook onions

Heat butter and 1 tablespoon olive oil in a medium skillet over medium-low heat until butter foams. Add sliced red onions and a pinch of salt. Cook gently, stirring frequently, for about 12–18 minutes until onions soften and begin to caramelize.

Caramelize and jam

Increase heat to medium, add brown sugar and thyme, and stir to combine. Let onions brown further for 3–5 minutes, then add balsamic vinegar and red wine (or water). Scrape up browned bits and reduce mixture over medium heat until syrupy and jam-like, about 6–8 minutes. Taste and adjust seasoning with 1 tsp salt and 1 tsp pepper if needed. Remove from heat and keep warm.

Toast bread

Brush both sides of sourdough slices lightly with olive oil. Toast in a hot skillet or under the broiler for 1–2 minutes per side until crisp and golden. If using butter, spread a thin layer on hot toast immediately after cooking.

Assemble & serve

Spoon a small mound of warm red onion jam onto each toast. Using a small spoon, scoop warm roasted marrow onto the jam (or serve marrow in bones with toast on the side for guests to spoon themselves). Sprinkle parsley-lemon mixture over marrow, finish with a pinch of flaky sea salt and an optional squeeze of lemon. Serve immediately while marrow is warm and spreadable.