Cut the pork belly into bite-sized pieces.

Slice the green onion diagonally into 1cm pieces.

Bring 300ml of water to a boil in a pot and add the pork. Cook over medium heat until the pork changes color, skimming off any foam.

Add the green onion and seasonings (chicken stock powder, salt, pepper). Stir and simmer for 3 minutes.

Mix cornstarch and water to create a slurry, then add it to the pot to thicken the broth. Pour in the beaten egg slowly.

Microwave the frozen udon noodles according to package instructions, then place them in a serving bowl.