Soak 2 oz (60g) of glass noodles (dangmyeon) in warm water for about 15 minutes. (If you have more time, you can soak them in cold water for about an hour. For the chewiest texture, always let the noodles absorb water before exposing them to heat.)

Halve 2 green onions (about 5.3 oz/150g) lengthwise and cut them into large pieces. Thinly slice ¼ onion (about 1.8 oz/50g).

Gently whisk 2 eggs in one direction with chopsticks until evenly blended, avoiding excessive frothing. (Whisking too vigorously can incorporate air, creating foam, making the cooked eggs tough, and clouding the broth. You don't necessarily need to remove the chalazae (egg white strands), but you can if you're particular about texture.)

In a pot, add 2 tbsp cooking oil and 1 tbsp sesame oil (chamgireum). Add the prepared green onions and onion, mix well, then turn on the heat to medium-low. Sauté until fragrant. (Lightly tossing the ingredients with the oil before turning on the heat helps them cook evenly without burning. Adding sesame oil at this stage makes the broth feel less empty when cooking without stock, and prevents the oiliness from being overwhelming.)

Reduce heat to low, add 1 tbsp minced garlic, and stir-fry briefly until fragrant, taking care not to burn it. Then turn off the heat. (Adding garlic later allows the moisture from the green onions and onion to prevent the garlic from being directly exposed to high-temperature oil, reducing the chance of burning and bitterness, making it easier to develop its aroma.)

Add 1 tbsp coarse Korean chili powder (gochugaru) and 1 tbsp fine Korean chili powder (gochugaru). Mix well with the residual heat first, then turn the heat back to low and stir-fry briefly for less than 30 seconds. (Chili powder can easily burn on high heat, leading to a bitter taste. Therefore, mix it thoroughly with the oil while the heat is off, then stir-fry on very low heat just until chili oil starts to develop. Coarse chili powder adds aroma, while fine chili powder adds color and spiciness, so using both creates a much more complex flavor.)

Add 1 liter of water, 3 tbsp tuna sauce (chamchieok), and 1 tbsp Korean soup soy sauce (guk-ganjang). Bring to a boil. Skim off any foam that forms while boiling to achieve a cleaner broth.

Once it comes to a boil, taste the broth. Season with ½ tsp salt if needed. (The seasoning will mellow slightly after adding the glass noodles and eggs, so it's best not to make it too bland at this stage.)

When it boils again, add the soaked glass noodles and cook for about 2 minutes.

Slowly pour in the eggs bit by bit, let them sit for about 5 seconds, then turn off the heat and gently swirl to cook them softly. (If you stir the eggs immediately after adding them, the broth will become cloudy and the eggs will disperse.)

Serve in a bowl and finish with a sprinkle of black pepper.