Peel and wash the potatoes and cut them into halves or quarters depending on their size. Boil potatoes for about 15 minutes. Clean and wash the cauliflower and cut into florets. Cook in little boiling salted water for about 6 minutes. Dice ham. Peel and finely dice onion.
Drain potatoes and cauliflower and let them drain. Heat 2 tablespoons of butter in a saucepan. Brown the ham in it. Take out. Fry onion in frying fat until translucent. Dust with flour and sauté briefly. Deglaze with 1/4 litre water and milk. Bring to the boil, stir in broth and simmer for about 5 minutes. Season to taste with salt, pepper and nutmeg. Mix potatoes, cauliflower and ham and spread in an ovenproof dish. Pour sauce over it. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes.
Bring to the boil, stir in broth and simmer for about 5 minutes. Season to taste with salt, pepper and nutmeg. Mix potatoes, cauliflower and ham and spread in an ovenproof dish. Pour sauce over it. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes. Crumble bread and knead with 1 teaspoon of butter. After approx. 20 minutes baking time, spread on the casserole and bake until done. Garnish with basil if necessary