01 -
Melt butter in a skillet over medium-low heat. Add sliced onions with a pinch of salt and cook slowly, stirring occasionally, for 20 to 25 minutes until golden brown and soft. Reserve off heat.
02 -
In a bowl, whisk eggs, milk, salt, pepper, and nutmeg until the mixture is smooth. Allow to stand for 5 minutes to dissipate bubbles and create a glassy surface.
03 -
Preheat oven to 160°C. Evenly divide caramelized onions between two heatproof ramekins (approximately 120 ml each). Gently pour egg mixture over onions, filling each ramekin three-quarters full. Distribute crumbled cheese evenly over the surface. Let ramekins rest for 5 minutes.
04 -
Set ramekins in a deep baking dish and pour hot water into the dish until it reaches halfway up the sides of the ramekins. Bake for 25 to 30 minutes, or until the custard is set but the centre remains slightly wobbly.
05 -
Remove ramekins from the water bath and allow to cool for 5 minutes. Serve warm or at room temperature, optionally garnishing with fresh herbs.