Potatoes à la Normande (Gratin with Leek and Milk)

Ingredients

• 100 grammes white of leek
• half an onion
• butter
• 1 spoonful flour
• three quarters of a litre boiling milk
• salt
• pepper
• nutmeg
• 1 kilo potatoes
• 1 bouquet garni

Instructions

1. Cook 100 grammes of sliced white of leek and half a sliced onion in butter, without letting them colour.
2. Sprinkle with a spoonful of flour.
3. Moisten with three quarters of a litre of boiling milk and season with salt, pepper and nutmeg.
4. Add 1 kilo of potatoes sliced coin-thin and a bouquet garni.
5. Cook gently.
6. Pour into a deep dish and gratinate the surface.