Heat oil in a pot over medium-high heat.
Once the pot is hot, add the chopped onion and the white parts of the green onion, and sauté for about 2 minutes until the onion becomes translucent.
Stir in the Korean red chili flakes, miso paste, and minced garlic until everything is well combined.
Pour in your choice of stock and bring the mixture to a simmer.
Once it starts to simmer, add the noodles and any additional toppings you prefer.
Garnish with the remaining green onion and enjoy your soup!
