1. In a large bowl, whisk the eggs, milk, nutmeg, a pinch of salt, and pepper.

2. In a pan, over medium heat, heat the oil and butter. Add the beaten eggs.

3. Increase the heat and, with a small spatula, bring the cooked parts towards the center, as the eggs cook, until the omelette is still fairly soft (runny).

4. Quickly, add the ham, arugula, and mozzarella slices to the omelette. Roll the omelette to enclose the filling. Cover the pan and let it wait off the heat for 3 minutes before serving. Serve with a crispy baguette.