Preheat oven to 400°F (200°C) and prepare the baking rack on the bottom slot of your oven.

Unroll the pie crust and line a 9-inch pie plate. Trim and fold edges under.

Prick the crust with a fork, line with parchment paper, and cover with weights. Bake for 20 minutes, then remove weights and bake for an additional 5 minutes.

In a small skillet, heat butter and sauté shallots until browned. Remove from heat.

In a bowl, whisk together eggs, cream, mustard, salt, and pepper.

Spread sautéed shallots, spinach, and half of the cheese onto the baked crust. Pour the egg mixture over it.

Top with remaining cheese and grated nutmeg. Bake for 25-30 minutes until set.

Let the quiche rest for 10-20 minutes before slicing. Serve warm or at room temperature.