You can prepare the spinach mixture ahead and time and then reheat in the morning, crack the eggs and bake. The dish can be served with or without the hollandaise sauce.
I used this recipe for the hollandaise sauce and added 3/4 teaspoon of Celtic sea salt to the sauce to get just the right flavor
Dash of cayenne pepper
Instructions
Preheat oven to 500 degrees F and adjust rack to middle position. Melt the butter in a medium sauté pan over medium heat. Add the shallot and cook, stirring frequently until soft, about 3 minutes. Add the spinach and cook until the spinach has wilted and released its moisture, about 5-7 minutes. Add the coconut flour and stir constantly for 1 minute. While constantly stirring, slowly pour in milk and cook for about 2 minutes until thick. Remove from the heat and stir in cheese, dry mustard, and salt.
At this point, you can divide the spinach mixture between two individual pans, or you can make 4 small wells using the back of a spoon and crack the 4 eggs into the wells. Bake for 6-8 minutes, just until whites are set. Serve alone or with hollandaise sauce and a dash of cayenne pepper.