Prepare oatmeal and tuna.
Place oatmeal in a bowl and pour hot water over it.
Let it soak for 2-3 minutes until the oatmeal is moist.
Drain the oil from the tuna and add it to the oatmeal, mixing well.
Season with salt, pepper, or other preferred seasonings.
Add chopped vegetables or onions if desired.
Mix everything together and serve.