Method:

1. Peel the potatoes, cut them once lengthwise and bring them to boil in cold salted water. 

2. Put on a casserole and bake the spinach in some butter. Season with pepper, salt and nutmeg. Add the cream and allow to braise until the mass has thickened.  

3. Portion the fish and arrange in a greased oven trey. Season with pepper and salt, some thyme, and allow to bake in the oven for about 7 minutes (180°C).

4. Drain the potatoes, put them back on the range, low heat, and allow excess water to evaporate from the potatoes.

5. Mash the potatoes and season with nutmeg, pepper, salt and add the eggs, milk and some butter. This mash should be juicy.

6. Take the fish out of the oven and drain excessive moist. Put a layer of spinach, then a layer of potato mash.

7. Add the breadcrumbs and allow to color in the oven.