In a medium saucepan, melt butter over medium heat. Add onion and garlic; cook until tender, about 5 minutes. Slowly whisk in flour; cook, whisking constantly, for 2 minutes. Add cream, and whisk until creamy and beginning to thicken, 2 to 3 minutes. Slowly add spinach, a handful at a time, letting it wilt before adding more. Stir in pepper, salt, and nutmeg.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/eggs-sardou-recipe/