Bone Marrow Soup
Ingredients
5 pounds (2.3kg) beef marrow bones, cut crosswise into 2-inch pieces (see note)
2 bone-in beef shanks (about 2 1/2 pounds)
Kosher salt and freshly ground black pepper
2 ears sweet corn, shucked
4 tablespoons (75ml) canola or other neutral oil, divided
2 medium garlic cloves, minced
1/2 medium red onion (4 ounces; 115g), cut into 1/8-inch-thick slices (reserve trimmings)
1/2 Napa cabbage (1 pound; 450g), cut into 3-inch-thick slices (reserve trimmings)
2 scallions, ends trimmed and sliced thinly on a bias, for garnish (reserve trimmings)
1 pound (450g) beef tendons, rinsed and patted dry with paper towels (optional)
1 pound (450g) beef knuckles, rinsed and patted dry with paper towels (optional)
Fish sauce, to taste
1 pound (450g) yellow fingerling potatoes (about 5 to 7 potatoes), scrubbed and cut into 2-inch pieces
Instructions
Rinse marrow bones and beef shanks under cold running water. Transfer to a large bowl, cover with cold water, and let soak for 1 hour. Rinse, pat dry with paper towels, season with salt and pepper, and set aside.
Meanwhile, Preheat Oven to 425°F (218°C). In a medium bowl, toss corn with 1 tablespoon (15ml) oil. Place on rimmed baking sheet and roast, rotating corn after 15 minutes, until corn is tender and lightly browned, about 30 minutes total. Set aside until cool enough to handle, about 15 minutes.
To remove kernels from the cobs, place a large bowl on your work surface and invert a small bowl within the large bowl (this serves as a base on which to rest the corncob). Working with one at a time, place one end of a cob on the inverted, smaller bowl. Using a chef’s knife, slice downward, as close to the base of the kernels as possible while taking care not to angle the blade into the cob itself. Rotate the ear of corn, and continue until all the kernels have been removed. Repeat with remaining ear of corn. Set aside; reserve cobs.
In a Dutch oven or stockpot, heat 1 tablespoon (15ml) oil over high heat until shimmering. Using tongs, add shanks and cook, turning occasionally, until well browned on all sides, about 5 minutes. Transfer to plate; set aside. Add garlic and onions to stockpot. Cook, stirring frequently, until garlic is golden brown and onions are translucent, about 3 minutes. Scrape onto plate with shanks.
Add reserved corn cobs and reserved onion, cabbage, and scallion trimmings to stockpot and cover with water. Bring to a boil over high heat and cook for 10 minutes. Lower heat to maintain a simmer and continue to cook for 30 minutes. Using a spider skimmer, remove cobs and trimmings, and discard.
Add reserved shanks, garlic and onion, beef tendons (if using), and beef knuckles (if using) to stockpot (be sure to check the water level; if the shanks, tendons, and knuckles are not fully covered, add water as needed). Bring to a boil over high heat and cook for 30 minutes. Lower heat to maintain a simmer, partially cover with lid, and continue to cook until tender, about 1 1/2 hours. Add cabbage, cover, and cook until cabbage is tender, about 10 minutes. Stir in fish sauce, 1 tablespoon at a time, until sufficiently seasoned.
Meanwhile, line two rimmed baking sheets with aluminum foil. In a large bowl, toss potatoes with remaining 2 tablespoons (30ml) oil, then season with salt and pepper. Transfer to a prepared baking sheet. Roast potatoes until crispy on the outside and fork-tender on the inside, about 20 minutes.
Place marrow bones on second prepared baking sheet. Roast marrow bones until crisp, brown on the edges, and marrow is soft and pulling away from the bone, about 20 minutes.
To serve, divide marrow bones, shank, tendons, and knuckles between soup bowls. Top with cabbage, potatoes, and corn. Ladle broth on top, garnish with scallions, and serve hot with white rice.