In a saucepan, over high heat, whisk the cream together with the sugar and vanilla bean.
Bring to a simmer and remove from the heat.
In a bowl beat the egg yolks until thick and frothy.
Temper the egg yolks by stirring just 1/4 cup of the sauce into the yolks, until incorporated.
Turn the egg yolk mixture into the sauce and stir until thoroughly blended. Return the saucepan to low heat and cook 2 to 4 minutes, stirring often to prevent scorching.
Remove from the heat. Strain through a fine mesh sieve.