Preheat oven to 450°F (230°C). Line a rimmed baking sheet with foil for easy cleanup, then place a wire rack on top so bones sit elevated. Pat marrow bones dry with paper towels.

Season bones: brush the exposed marrow and cut sides lightly with neutral oil, then season with kosher salt and freshly ground black pepper. Arrange bones marrow-side up on the wire rack so heat circulates evenly.

Roast: transfer to the preheated oven and roast for 15–20 minutes, until the marrow is bubbling at the edges, has softened but still holds a slight shape (do not overcook — marrow should be soft and spreadable, not melted away).

Rest briefly: remove bones from oven and let rest 2–3 minutes — marrow will firm slightly and be easier to spoon out.

Herb-citrus gremolata (emulsion style)

Prepare gremolata

While the bones roast, make the emulsion-style gremolata. Combine parsley leaves, cilantro (if using), lemon zest, orange zest, garlic clove, and capers in a small food processor or blender.

Pulse briefly until herbs are finely chopped but still bright (avoid pureeing into a paste — you want a coarse, emulsified texture).

With the motor running, drizzle in the extra-virgin olive oil slowly to form an emulsion around the herbs. Add red wine vinegar and Dijon mustard, pulse once to combine.

Season the emulsion with sea salt and freshly ground black pepper to taste. Taste and adjust acidity or salt as needed. The result should be a bright, loose emulsion that will contrast the richness of the marrow.

If the emulsion seems too thick, thin with up to 1 teaspoon water or more olive oil, 1 tsp at a time, until spoonable.

Accompaniments and plating

Toast bread: while marrow roasts, toast baguette slices under broiler or on a grill until crisp and golden on both sides. Rub each warm toast lightly with a cut garlic clove if desired.

Assemble: spoon warm roasted marrow into shallow dishes (or leave in bones) and top each portion with 1–2 teaspoons of the herb-citrus emulsion. The acidity and herbs will cut the fat and add brightness.

Serve immediately with toasted bread, cornichons or pickles on the side, and lemon wedges for squeezing. Recommend guests spread marrow on toast, add a touch more gremolata, and finish with a squeeze of lemon if desired.

Storage note: leftover marrow can be refrigerated in an airtight container for up to 2 days. Gremolata stores up to 3 days refrigerated; re-whisk before serving.