I found this one for you, have never made it, but it might make your Mum's recipe look simple!!
Flan, or Creme Carmel
This is a wonderful dessert after a rich or highly spiced meal, and it also makes a delightful snack. Creme Carmel is an old French specialty which they taught to the Mexicans during the time they ruled Mexico. The Mexicans have re-named it Flan, and have made it even better. Now it can be found all over Mexico, from the finest restaurant to the small street vendor, and is enjoyed by all. This version is nicely sweet, light as a maidens breath, and perfectly textured.
Bring gently to boil, stirring often:
4 ¾ cups milk
1 1/3 cups half and half
2 cups sugar
zest of one lemon
good grating of nutmeg
Cool milk mixture. While it is cooling, prepare the Caramel. In a heavy pan, bring to a boil:
2 cups sugar
¼ cup water
Stir until sugar is melted. Boil over high heat without stirring until sugar caramelizes to a light golden brown. Watch it carefully, it can go past the light brown stage quickly and burn. Pour into twelve custard cups and swirl carefully to coat bottom evenly about 1/8 inch thick. Be careful, this stuff really burns if you get it on you.
While the carmel cools, beat well together:
12 egg yolks
8 whole eggs
When milk mixture has cooled to lukewarm, beat the eggs gently in, then strain. Pour into the prepared custard cups. Dust with a delicate touch of cinnamon and/or nutmeg. Stand cups in baking pan and carefully fill pan with enough hot water to come about half way up sides of cups. Bake at 300? about one hour or until knife or bamboo skewer inserted in center of cup comes out clean.
Let the Flan cool to lukewarm, or chill well. When ready to serve, run knife carefully around inside of each cup. Turn out gently onto serving plate. Garnish with a bit of mint and a dollop of whipped cream.