MANDUGUK

Steps:

• Trim chuck roast and cut into 1 1/2-inch thick by 1 1/2-inch wide strips. Quarter onion, leaving roots intact.
• Place beef and onion in a large pot with light scallion parts, garlic, ginger, and peppercorns. Add water and bring to a boil over high heat, skimming off any foam that rises to the surface. Reduce heat to low and cover with a lid, leaving it slightly askew. Cook, adjusting the heat as needed to maintain a gentle boil, until beef is tender and easily pierced with a knife, about 1 hour 30 minutes. Turn off heat.
• Transfer beef to a heat-proof bowl and spoon some of the cooking liquid over top to moisten. Let rest until cool enough to handle, about 20 minutes, then shred into bite-sized pieces.
• While the beef is cooling, strain broth over an 8-cup heat-proof measure. Discard solids and return broth to the pot. Stir in fish sauce, salt, and pepper.
• Separate 1 egg into 2 small bowls; stir egg yolk until runny.
• Heat 1 teaspoon canola oil in a small nonstick skillet over medium-low heat. Rub oil with a paper towel to coat sides and bottom of the skillet with a thin layer. Scrape egg yolk into the skillet with a rubber spatula. Remove from the heat and swirl to evenly coat the bottom of the skillet. Return to the heat and cook, undisturbed, until egg yolk is pale-yellow and the surface looks dry, about 1 minute. Turn off heat and gently flip with a spatula. Let sit for 1 minute, then transfer to a cutting board. Cut egg yolk sheet in half, then slice crosswise into thin strips. Wipe the skillet clean.
• Prep and heat the skillet in the same manner with the remaining 1 teaspoon canola oil and a paper towel. Cook egg white until it turns opaque and bubbles form on the surface, about 45 seconds. Turn off heat and let sit until set, 1 to 2 minutes. Gently transfer to a cutting board and slice as you did for the egg yolk sheet. Set aside.
• Return broth to a boil over high heat. Add dumplings and cook until they float and reach an internal temperature of 165 degrees F (74 degrees C), 5 to 7 minutes. Reduce heat to a gentle simmer over medium.
• Slowly drizzle beaten eggs into the simmering soup. Cook until eggs set, about 5 seconds. Remove soup from heat and stir in reserved dark green scallion parts, sesame oil, and additional salt to taste.
• Ladle soup into bowls and top with egg white and egg yolk strips. Garnish with nori.