• Peel the potatoes and cut them into thin slices about 3mm or so with a knife or potato peeler. Keep aside.
• If you use dried porcini, place them in a cup with hot water for 5 minutes. Then drain, strain the water, and combine it with the broth. Rinse the mushrooms, chop with a knife, and set aside.
• Clean and slice the mushrooms and set aside.
• Preheat the oven to 180C degrees (356F).
• Grease the bottom of the baking dish with oil or butter, arrange a layer of potatoes, sprinkle with Parmesan cheese, spread the mushrooms over the surface, a few porcini crumbs here and there, a handful of rice (divide it equally among the layers), a pinch of salt, add a few ladles of broth to which you will have added the soaking water from the porcini, and proceed with another layer.
• Repeat the same procedure for each layer until you run out of ingredients. Don't forget to add a pinch of salt for each layer.
• Make a final layer of potatoes, sprinkle with Parmesan and oregano or dried thyme, and add a few flakes of butter and more broth if the pan contains it. Set aside a few spoons of it to add while cooking.
• Cover the pan with aluminum foil and bake in a preheated oven for 20 minutes. Remove the cover and continue cooking for another 10 minutes. Sink a toothpick into the baking dish and add a couple of ladlefuls of broth if it looks like you need to.
• Let stand 10 minutes before serving.

Food Tips

• All ingredients are not pre-cooked: potatoes, mushrooms, and rice.
• If you reheat it, cover the pan with aluminum foil.
• You can prepare it the day before.
• Store in the refrigerator.