- Approximately 1kg (2.2 lb) potatoes, scrubbed (you can peel if you prefer but it will lower the nutritional value)
- 1 Tablespoon butter
- 4 cups milk
- 1/3 cup flour
- 1 packet instant mushroom soup or 3 tsp instant vegetable stock
- 1 cup grated cheese
- 1 tin tuna in oil
- 1 packet potato chips (flavor of your choice)
Boil potatoes for 20 minutes until just cooked. Drain, roughly chop into 1cm (1/3 inch) slices and place in the bottom of a large oven-safe casserole dish.
Heat three cups of the milk in a saucepan and add the butter. Do not boil.
Shake (in a shaker or screw-top jar) the remaining cup of milk, the flour and the mushroom soup mix (or instant stock).
When the butter has melted, add the milk/flour mixture to the pan.
Turn up the heat and stir until the mixture just boils. It is important to keep stirring as the sauce thickens or else it will go lumpy and stick to the bottom.
When the sauce has just boiled, take off the heat and add the cheese and all the contents of the fish tin, chopping fish if necessary.
Pour the mixture from the pan over the top of the potatoes in the over-proof dish.
Bake in the oven until heated through (about 25 minutes at 200 degrees celsius, 390 F).
Leave to cool for 10 minutes then top with crushed potato chips and serve.