All ingredients ready? Let's begin!
In a 12-inch heavy-bottomed and oven-proof skillet, preferably cast iron, over medium heat, melt the butter. Add the onions and cook until softened. This will take approximately 5 minutes, stirring often.
Squeeze any excess moisture out of the spinach. Add it to the onions in the pan and cook until warmed through, about 2 minutes.
Stir in the cream, milk, and nutmeg. Cook, stirring often until the liquid has nearly evaporated, approximately 8 minutes. Add the cream cheese, parmesan, salt, and pepper. Stir well until the cheese is incorporated throughout. Transfer the creamed spinach to a large bowl and allow it to cool.
Preheat your oven to 425°F. Using a paper towel, wipe out the skillet.
Return the skillet to the stove and turn the heat to medium-high. Add the olive oil and the garlic. Cook the garlic until it is fragrant, about 1 minute. Add the Italian herbs to the pan and cook another 1 minute.
Add the ground beef to the pan and cook until completely browned. Break the meat up with a wooden spoon. This step should take about 5 minutes. Season with salt and pepper and a couple of dashes of Worcestershire sauce. Stir well and then spread the meat out into a single layer in the pan. Remove from the heat.
Add the beaten eggs to the spinach mixture and stir well to combine everything. Using a silicon or rubber spatula, spread the spinach over the beef in a single layer.
Arrange the tater tots in a nice circular pattern over the spinach.
Brush the tots lightly with olive oil. Place the skillet in the oven and bake until golden brown and bubbling hot, approximately 40 minutes.
Slice the casserole into wedges as you would a pie and serve while warm.