In a deep skillet or wok, heat up 2 tbsp of cooking oil. Add garlic, spring onions, and chilli flakes and stir-fry for a few minutes. Be careful not to burn the chilli flakes, as they become bitter when burned.
Add the fermented shrimp and stir-fry for another 1-2 minutes.
Add water and bring to boil. Add udon noodles and soondubu. Divide soon dubu into equal pieces using a spatula. Let simmer for 1-2 minutes or until noodles are al dente.
Crack one egg into a medium bowl and whisk until smooth and combined. Slowly pour the whisked egg into the broth in a circular motion. Don't stir the broth before the egg firms up.
Season with salt and miwon/msg to taste.
In a large bowl, place one handful of washed mungbean sprouts. Pour broth and noodles on top and garnish with sesame oil, sesame seeds and seaweed flakes.