Soak the seaweed in cold water for 10 minutes, then chop it finely.
Rinse the oatmeal with water and set aside.
Add tuna to a pot and stir-fry over medium heat.
Add the soaked seaweed and stir-fry together.
Pour in 500ml of water and bring to a boil.
Add the oatmeal and stir for 5 minutes while boiling.
Season with salt to taste and finish.