This is a first for me, as I came across this recipe lately, browsing through the pages of a new Italian cookbook I recently purchased. Although it did not turn out just like the picture in the book, I was pretty satisfied and I probably figured out where I could improve. This is basically the same recipe for traditional gnocchi, without the frozen spinach (white gnocchi). Instead of making little potato dumplings, you keep the whole dough as one piece and you flattened with a rolling pin (or wit your hands!) until it is about 1/4 inch thick. It is better if you do it already on a kitchen rag as it might be difficult to move the dough once it is flattened (see picture).
At this time you can place on the flattened dough your favorite ingredients. I went for some sliced white mushrooms cooked in butter and garlic, and then finely chopped into a sauce using a blender. I spread the mushroom sauce on a thin layer of shredded mozzarella e Parmesan cheese and topped it with fresh spinach leafs.
Carefully, I rolled the dough using the rag and then tied the two extremities with a string. Make sure the rag is as tight as possible around it. That will give it a nice and firm cylindrical shape to the final cooked product. Place the whole thing into a large pan with boiling salted water for 30 minutes. Remove it from the pan and let it sit, still in the rag, until it has cool down (15-20 minutes). This is an important step as it will ensure that the large rolled dough keeps its cylindrical shape once you untie the ends and remove the rag.
At this point you can slice it and place the slices in a baking pan. Cover with small pieces of butter and with parmesan cheese and baked at 350F for few minutes, until cheese has melted. Enjoy!