Heat the oven to 325F and put a kettle on. Have a deep roasting tin ready and a 9 inch round cake tin or 8 individual ramekins.

For the caramel, put the sugar in a dry heavy pan over medium heat. Leave it alone until it starts to melt at the edges, then swirl the pan, without stirring, until it is fully liquid and the colour of an old penny.

Pour it straight into the tin and tilt to cover the base. It will set hard within a minute, which is expected.

Whisk the eggs just until the yolks and whites are combined, with as little foam as possible.

Whisk in the condensed milk, evaporated milk, vanilla and salt until smooth.

Pour the custard through a fine sieve into the caramel-lined tin. Skim off any bubbles on the surface.

Set the tin inside the roasting tin and pour boiling water into the outer tin to come halfway up the side of the custard. Cover the whole thing loosely with foil.

Bake 55 to 65 minutes, until the edges are set and the centre wobbles as a single mass when you nudge the tin, rather than rippling in waves.

Lift it out of the water, cool to room temperature, then refrigerate at least 6 hours and preferably overnight.

To serve, run a thin knife around the edge, put a plate over the tin, and invert in one confident movement.