Method

Cook leeks:

• Preheat the oven to 150C.
• Wash the leeks well in cold water to remove as much dirt as possible. Drain.
• Set a fry pan over medium-high heat, add the butter and add the leeks.
• Season with salt and cook, stirring often, for about 5 minutes. 
• As the leeks begin to soften, lower the heat to medium-low. The leeks will release liquid. Cover the pan with a lid, and cook, stirring every 10 minutes, until the leeks are soft, about 15-12 minutes. Remove from the heat and take off the lid.

Make croutons:

• Meanwhile, spread the bread cubes on a baking tray and toast in the oven for about 20 minutes, give the pan a shake about halfway through and continue to bake until dry and lightly golden.
• Transfer the toasted cube to a large bowl and leave the oven on. Add the leeks to the bread and toss well, then add the herbs.

Make egg custard:

• In another large bowl, lightly whisk the eggs. Whisk in the milk, cream, a generous pinch of salt, pepper to taste, and a pinch of nutmeg.

Assemble the pudding:

• Sprinkle ¼ cup of cheese in the bottom of an 18cm by 20cm baking pan
• Spread half the leeks and croutons in the pan and sprinkle with another ¼ cup cheese
• Scatter the remaining leeks and croutons over and top with another ¼ cup cheese
• Pour in enough of the custard mixture to cover the bread and press gently on the bread so it soaks in the milk. Let soak for about 15 minutes.
• Add the remaining egg custard mix, allowing some of the soaked cubes of bread to stick through as this when baked will be crispy.
• Sprinkle the remaining quarter cup cheese on top and sprinkle with salt.
• Bake for 40 minutes, or until the pudding feels set and the top is brown and bubbling.
• Serve immediately.