To make the custard (which is thinner than if you would be making it to pour) whisk the egg yolks, eggs and sugar together and then whisk in the milk and cream. I have tried the custards where you heat the milk and cream first and I think it makes no real difference. This way is much quicker and easier.
Pour the custard over the bread and leave it to rest for 20-30 minutes so that the custard has a chance to seep into the bread and make a gooey mess. I find you’ll probably need to push the bread into the custard to ensure it all gets a good bathing.