Ingredients:
4 medium eggs
200g (1 cup) caster sugar
4 lemons - juice and zest
100g (1/2 cup) unsalted butter, diced
Method:
Lightly beat the eggs (4 eggs) and place them into a microwave-safe bowl with the caster sugar, lemon juice and lemon zest. Beat lightly with a fork to mix everything well.
Turn your microwave down to about 500W. Cover the bowl and then heat the lemon/egg/sugar mixture in your microwave for 30 seconds. Remove from the microwave and whisk. Repeat the heating and whisking until the lemon curd has thickened (it should coat the back of a spoon when done).
Once thickened, add the butter and stir until the until completely melted.
To make lime curd, substitute the lemons with 6 limes. For grapefruit curd substitute the lemons with 1 grapefruit.