You will need:
- A couple of bits of salmon fillet.
- A sweet potato, about the size of one and a half clenched fists.
- A tin of peas.
Put the kettle on.
Peel the sweet potato and cut it up into pieces about the size of the last joint of your thumb.
Wait for the kettle to boil.
Put some of the water from the kettle into a saucepan with the sweet potato, and put it on the heat.
Put the salmon fillets into a dish, and pour the remainder of the boiling water over them to cover.
Shake the dish gently to ensure that they aren't sticking to the bottom or sides of the dish, or to each other.
Cover the dish and put it to one side and forget about it.
Get the peas out of the tin, and warm them up in a small saucepan or a microwave.
When the sweet potato is cooked (it falls off a knife when you stab it) then lift the fish out of the hot water.
Put all the stuff onto plates and eat it.
Bask in the admiration of your girlfriend and patiently explain that you haven't done anything difficult.