Granny made this whenever a friend in the country had given her some freshly laid eggs. Together with warm seedy brown bread and a watercress salad, I thought it was a perfect meal.
For the custard, lightly whisk the eggs in a large bowl. Heat the milk in a pan to just below the boil, add the cheese and stir until smoothly melted in, then slowly whisk into the eggs. Grate the nutmeg onto the mixture and stir in, along with the mustard and a good seasoning of sea salt and black pepper. Pour into the prepared dish.
Stand the dish in the roasting pan of warm water in the oven.
Meanwhile, make the sauce. Melt the butter in a saucepan over a low heat, then, off the heat, stir in the flour. Gradually stir in the milk, then return to the heat and bring to the boil, stirring. Lower the heat and simmer for 2-3 minutes, stirring. Remove from the heat and stir in the grated Gruyere. Once melted, stir in the egg yolk thoroughly. Season with cayenne pepper to taste, and salt if needed. Snip the chives finely into the pan and stir in.
When the custard is ready, heat the grill. Pour the sauce slowly over the custard and finely grate the Parmesan over the top. Briefly put the dish under the hot grill until speckled brown. Serve as soon as you can.
© 2010 Josceline Dimbleby. All rights reserved.