Classic French Spinach Quiche Recipe

Ingredients

• 1 (9-in) deep dish frozen pie crust
• 1 tablespoon butter
• ½ cup thinly sliced shallots, from 2 medium shallots
• 4 large eggs
• 1¼ cups heavy cream
• Pinch ground nutmeg
• ¾ teaspoon salt
• ⅛ teaspoon cayenne pepper
• 1 cup (4 oz) finely shredded Gruyère, packed
• 1 (10-oz) package frozen chopped spinach, (defrosted and wrung free of water)