Step 1

Melt 1/4 cup of butter in a medium-sized pot over medium heat. Whisk in the flour and cook for a couple of minutes until light golden. Add in the onion and cook until transparent (about 2-3 minutes), then add the garlic and cook until fragrant (about 30 seconds).

Step 2

Pour in the milk (or half and half), whisking constantly until the white sauce thickens (about 5 minutes). Season with salt, pepper, nutmeg and cayenne (If using). If the sauce is too thick, add another 1/4 cup of milk to the sauce, whisking it through until reaching your desired thickness.

Step 3

For the spinach: melt the remaining butter in a separate pan, and add spinach in batches, wilting each batch before adding the next, until all spinach is wilted. (Add a small spoon of water if the pan gets too dry.)Alternatively: Cook the spinach in a pot of boiling water for just one minute; then immerse in a cold water bath to stop the cooking process. Squeeze out any excess water from the leaves and set aside.

Step 4

Season the cream sauce with salt, pepper, nutmeg and cayenne. Add wilted spinach to the cream sauce, stirring gently to combine. Sprinkle with parmesan cheese and serve immediately.