Preheat oven to 375°F (190°C).

If using a store-bought crust, unroll and press it into a 9-inch pie dish. Trim excess.

For a homemade crust, roll it out to about 12 inches and fit into the dish. Chill for 15 minutes to prevent shrinking.

To blind-bake the crust, line it with parchment paper and fill with pie weights or dried beans. Bake for 12–15 minutes until edges are set. Remove the weights and parchment, then bake for an additional 5 minutes.

Heat 2 tbsp of butter or olive oil in a skillet over medium heat.

Add sliced scallions and sauté for 1–2 minutes until softened.

Add asparagus pieces and toss for 3–4 minutes until just tender. Season with salt and pepper.

In a medium bowl, whisk together the eggs, milk (and cream if using), Dijon mustard (if using), salt, pepper, and nutmeg.

Stir in half the cheese and the sautéed vegetables. Taste and adjust seasoning.

Optional: Brush the blind-baked crust with Dijon mustard or an egg wash.

Sprinkle remaining cheese evenly over the bottom of the crust and pour the egg-vegetable mixture over it.

Place the quiche on a baking sheet to catch any spills. Bake at 375°F for 35–45 minutes, starting to check at 30–35 minutes.

The center should just be set with a slight jiggle; the thermometer should read 160-165°F.

Let the quiche rest for 10–15 minutes before slicing.

Garnish with fresh herbs and serve warm or at room temperature.