Lemon Curd

Just very quickly, is the Lemon Curd recipe I promised MM:

LEMON CURD

2 large or 3 small lemons
4 large eggs
6 oz caster sugar (3/4 cup I think)
4 oz unsalted butter (1/2 cup I think)

Grate rind of lemons, making sure not to include any pith, into a basin. Add sugar. In another basin, beat eggs well with juice from the lemons. Pour over lemon rind and sugar. Add butter, cut into small pieces, and place basin over a pan of hot water or use a double saucepan. Cook very gently, stirring frequently, until thick. This will take about 20 mins. Pour into warm jars and cover in the usual way. Store in a cool place nad use within 1 month of making.

(Vvariation: St Clement's Curd: replace 1 lemon with 1 large orange.)