Roasted Garlic and Bone Marrow Mashed Potatoes Step-by-step instructions

Before you start

Before you begin, ensure your oven is fully preheated to 450°F (232°C). Prepare your roasted garlic ahead of time so it is ready to be squeezed into the potatoes. Have your potato ricer, a sturdy whisk or spatula, and a cast iron skillet ready on your workstation.

Keep your marrow bones in the refrigerator until the exact moment you are ready to roast them to ensure proper food safety. Gather all remaining ingredients and seasonings, keeping them within easy reach to maintain a smooth flow during the preparation and assembly phases.

Instructions

Potato Preparation

1. 1Prepare the Potatoes
   Using a potato ricer, process the baked Yukon Gold potatoes into a large mixing bowl. Add the squeezed roasted garlic, heavy cream, and butter. Whip the mixture until light and airy, ensuring all ingredients are fully incorporated into a smooth, consistent base.
   Look for The mixture should look smooth and creamy without any large lumps of potato.
   Tip Ensure the potatoes are still warm when ricing to prevent a gluey texture.

The mashed potatoes should be perfectly smooth, creamy, and well-seasoned with the roasted garlic. If you notice any large lumps, pass the mixture through the ricer once more. The texture should feel luxurious and hold its form when swirled with a spoon, signaling that the starch and fats are fully emulsified. If the mash seems too stiff, add an extra tablespoon of heavy cream at a time until you reach the desired consistency.

Marrow Roasting

2. 2Roast the Marrow Bones
   Place the split beef marrow bones on a baking sheet, seasoning them with rosemary sprigs. Roast in a preheated oven at 450°F (232°C) for 18 minutes. The marrow should be rendered and bubbling, reaching an internal temperature of at least 145°F (63°C) for safety. Let the bones rest for at least 3 minutes before proceeding.
   Look for The marrow will appear liquid gold and bubbling within the bone cavities.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Do not rush the roasting process as the marrow needs sufficient time to render its rich fats.

The marrow bones should be deeply golden and the marrow within should be bubbling with rendered fat. Use a thermometer to verify that the internal temperature has reached at least 145°F (63°C). The bones should smell savory and slightly nutty from the roasted rosemary. Ensure the marrow is fully liquefied before you attempt to scrape it into the potatoes, as this ensures the best distribution of flavor throughout the entire dish.

Final Broil

3. 3Assemble and Broil
   Fold the rendered liquid bone marrow into the prepared mashed potatoes until combined. Transfer the mixture into a cast iron skillet, creating swirls on the surface. Broil the skillet for 3 minutes until the potato peaks are golden and charred. Finish with parsley-caper gremolata and a sprinkle of flaky salt before serving immediately.
   Look for The peaks of the potato swirl should be golden brown and slightly crisp.
   Tip Watch the broiler closely to prevent the potato peaks from burning too quickly.

The finished dish should have beautifully charred, golden-brown peaks on the surface. The aroma should be a combination of roasted garlic, rich beef fat, and fresh herbs.

The gremolata should be scattered evenly over the top to provide a bright contrast to the dark, savory swirls. Check that the edges of the skillet are bubbling slightly, which indicates the dish is heated through and ready to be served immediately while the marrow is still warm.

Common mistakes

Avoid over-mixing the potatoes once the cream and butter are added, as this can lead to a gummy, glue-like texture. Do not skip the resting time for the marrow bones, as this allows the fats to stabilize.

Ensure the oven is at the correct temperature before starting, as a cooler oven will not render the marrow correctly, leading to a greasy rather than rich result. Finally, do not overcrowd the skillet during the broiling step, as this prevents the peaks from charring evenly, which is essential for the final texture.

How to tell it’s done

The mashed potatoes are done when they are light, airy, and hold their shape well when swirled. The marrow is properly cooked when it is completely rendered and bubbling, reaching an internal temperature of at least 145°F (63°C).

The final dish is ready when the peaks of the mashed potatoes are golden and charred from the broiler. Always ensure the marrow bones reach their safe internal temperature before folding them into the mash, and allow them to rest for at least 3 minutes before handling.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest