Preheat the oven to 350°F (175°C) and grease a 9-inch pie dish thoroughly with butter.
In a large bowl, whisk the eggs until smooth, then incorporate the cream, salt, pepper, and nutmeg.
Distribute the shredded cheese, spinach, bacon, and shallots evenly across the bottom of the greased pie dish.
Pour the egg mixture over the solid ingredients, ensuring they are evenly distributed.
Bake in the center of the oven for 40 to 45 minutes until the custard is set and the edges are slightly puffed.
Remove from oven and allow the quiche to rest for 10 minutes to stabilize the internal structure before slicing.