I think this is the perfect side dish to something like my Pork Chop Melts (#70596). It is very impressive when you bring it bubbling to the table.
- Sauté the onions in the butter over a low heat for 3-4 minutes.
- Add the hot chicken stock and let simmer 10 minutes more, covered.
- Stir in the flour and when it is completely mixed in, add the milk.
- Stir while bringing to a boil, then lower the heat and simmer for 3-4 minutes or until thick.
- Stir in two tablespoons of the parmesan, season with salt and pepper and set aside.
- Meanwhile, lightly sauté the spinach in a separate pan.
- When it is wilted, rinse in cold water until it is cool enough to handle.
- Chop roughly and spread over the bottom of a small casserole dish.
- Sprinkle over half the remaining parmesan and the nutmeg.
- Pour over the sauce and finish with the breadcrumbs and the last of the parmesan on top.
- Bake at 200 C or 400 F for 20 minutes.
- The gratin is done when it is bubbling and crusty on top.
- Serve immediately.