Step 1: Prepare the crust

• In a food processor, pulse together the flour, salt, and cold butter until the mixture resembles coarse crumbs.
• Gradually add ice water, 1 tablespoon at a time, and pulse until the dough just comes together.
• Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.
• Roll out the dough on a floured surface and fit it into a 9-inch pie pan. Trim the edges and chill in the refrigerator for 15 minutes.
• Preheat the oven to 375°F (190°C). Line the crust with parchment paper and fill it with pie weights or dried beans.
• Bake for 15 minutes, remove the weights, and bake for an additional 5 minutes until lightly golden.

Step 2: Prepare the filling

• In a large bowl, whisk together the eggs, heavy cream, milk, salt, pepper, and nutmeg (if using).

Step 3: Assemble the quiche

• Scatter the diced ham and grated Gruyère and cheddar cheeses evenly over the pre-baked crust.
• Pour the egg mixture over the filling, ensuring it spreads evenly.

Step 4: Bake the quiche

• Bake in the preheated oven for 35–40 minutes, or until the filling is set and slightly golden on top.
• Allow the quiche to cool for 10 minutes before slicing.

Step 5: Garnish and serve

• Garnish with fresh parsley and serve warm or at room temperature.