1. Prepare, cook and mash the potatoes.
2. Melt the margarine and beat half of it and the milk into the potatoes.
3. Place the potatoes in 7.5 cm, deep baking tins. Smooth over the top.
4. Use egg shell to make nests; break an egg into each.
5. Sprinkle the rest of the margarine over the top and place in a hot oven until the eggs are cooked and the potato is brown.
6. Serve hot.