Soak the seaweed in cold water for 5 minutes.
Cut the soaked seaweed into bite-sized pieces.
Add the tuna with its oil to a pan and stir-fry over medium-low heat.
Add the seaweed and stir-fry together for 2 minutes.
Pour in 400ml of water and bring to a boil.
Once boiling, add the oatmeal and stir while cooking for 3–5 minutes.
Season with salt and serve in a bowl.