Roasted Bone Marrow with Red Onion Jam
Chapter 4: Beyond the Steak
There is nothing subtle about dragging a spoon through roasted bone marrow and spreading it thick across charred sourdough. It is pure, unadulterated meat butter, the kind of unapologetic indulgence that defines the true American steakhouse experience. When properly purged in a saltwater bath and blasted at high heat, the marrow transforms into a wobbly, luxurious custard. Paired with a sweet and sharp red onion jam to cut the tremendous cholesterol load, this is the preamble to a great night—the kind of dish that makes you realize you don't need a reservation to eat like royalty.
Before you start
Purge the bones in a saline bath for 12 to 24 hours.
This step is non-negotiable for drawing out the blood and impurities that would otherwise turn the marrow grey and gamey. Place the bones in a container, cover completely with ice water, and stir in 1 teaspoon of coarse kosher salt per cup of water used. Refrigerate for 12 to 24 hours, replacing the pink water with fresh salted ice water every 4 to 6 hours until it remains clear.
Ingredients
- center-cut beef marrow bones4 large
- coarse kosher salt1/2 cup
- flaky sea salt1 tbsp
- black pepper1 tsp
- sourdough bread1 large
- garlic clove1 large
- extra virgin olive oil1/4 cup
- flat-leaf parsley1/4 cup
- red onions2 large
- unsalted butter2 tbsp
- dry red wine1/2 cup
- red wine vinegar1/4 cup
- dark brown sugar1/3 cup
- fresh thyme leaves1 tsp
Method
- 01
Sweat the red onions in butter and olive oil until they collapse.
In a heavy-bottomed cast-iron skillet or Dutch oven, heat the butter and 2 tablespoons of the olive oil over medium heat until shimmering. Add the sliced red onions and a large pinch of kosher salt. Cover and cook for 10 to 15 minutes, stirring occasionally, until the onions have softened completely without taking on dark, burnt colors.
- 02
Caramelize the onions with brown sugar.
Remove the lid, sprinkle the brown sugar over the onions, and stir. Allow the sugars to melt and gently caramelize the mixture for 5 minutes.
- 03
Deglaze and reduce to a thick, syrupy jam.
Carefully pour in the dry red wine and red wine vinegar, then stir in the fresh thyme. Reduce the heat to medium-low and simmer gently for 10 to 15 minutes. Stir occasionally until the liquid has almost entirely evaporated and dragging a wooden spoon across the bottom of the pan leaves a dry trail. Remove from heat, season heavily with black pepper, adjust the salt, and set aside.
- 04
Roast the purged marrow bones at blistering heat until they reach exactly 145°F.
Preheat the oven to 450°F. Remove the purged bones from their water, pat them aggressively dry with paper towels, and let them sit at room temperature for 30 minutes. Place them cut-side up on a foil-lined baking sheet, dust with kosher salt and black pepper, and roast in the upper third of the oven. Begin probing the center of the marrow with an instant-read thermometer at 15 minutes; pull them immediately when they hit 145°F (63°C), at which point they will be puffy and jelly-like.
- 05
Char the sourdough bread and rub with raw garlic.
While the bones roast, brush the thick sourdough slices generously with olive oil. Toast in a hot cast-iron skillet or grill pan until deep golden brown with charred edges. Immediately rub one side of each hot slice lightly with the raw, halved garlic clove so the abrasive crust melts the oils into the bread.
- 06
Assemble the marrow and serve immediately.
Transfer the hot canoe-cut bones to a warmed platter. Shower them with the chopped parsley and a generous pinch of flaky sea salt. Scoop the wobbly marrow onto the garlic-rubbed toast and top with a spoonful of the red onion jam.
Notes
Sourcing the canoe-cut.
Ask your butcher to split the long femur bones lengthwise on a bandsaw for the best presentation and even cooking. If they can only provide standard cross-cut cylinders, stand them upright like tree stumps on the baking sheet so the melting fat doesn't slide out.
Save the leftovers for bone marrow butter.
If you roast more bones than you can finish, scrape the leftover warm marrow into a bowl and mash it into softened, high-quality unsalted butter at a 1-to-2 ratio. Roll it into a log using plastic wrap, chill it, and use it to baste your porterhouse.