Step 1

Prepare the spinach: Defrost (if using frozen) and drain the spinach thoroughly. Squeeze out any excess liquid and set the spinach aside.

Step 2

Preheat the oven: 400f. Add cast iron pan to the oven (if using).

Step 3

Prepare ingredients: Using a deep sauté pan, melt the butter over medium heat. Stir in the chopped onions and garlic and cook them until they become translucent (around 15 minutes). Next, add the flour and nutmeg, and keep stirring for an additional 2 minutes. Then, add the cream and milk and continue to cook until the mixture thickens (around 7-8 minutes).

Step 4

Combine ingredients: Add the spinach and half of the parmesan cheese into the creamy sauce. Fold and stir until well combined. Taste and season the mixture with salt and pepper as needed. (This is your creamed spinach base)

Step 5

Bake the gratin: Transfer the creamed spinach mixture into a baking dish.If making creamed spinach: Put in the oven as is and bake for 20 minutes until it's heated through and bubbly.If making spinach gratin: Sprinkle the remaining parmesan and the gruyere cheese on top. Bake in the oven for approximately 20 minutes until it's heated through and bubbly.

Step 6

Serve and Enjoy: Serve while hot with a large serving spoon.