Rosette al Forno (Pasta Roses with Ham, Cheese & Mortadella)

Instructions

1. Prepare the pasta: Place the flour on a clean work surface and form a well in the center by creating a circular wall of flour with enough space in the center to hold the eggs. Crack the eggs into the well and start beating them with a fork, adding the flour bit by bit in a circular motion from the surrounding wall of flour to create a smooth dough that is moist, yet firm and not sticky. Once you’ve incorporated all of the flour into the eggs, gently knead the dough until it’s very smooth, pliable, and doesn’t stick to your hands. Add flour as necessary to achieve the right consistency. It should take about 10 minutes.
2. Form the dough into a ball, flatten it a bit, cover tightly in plastic wrap, and set aside at room temperature for at least 30 minutes to an hour to let the dough rest. You should have about 450 grams/1 pound of dough. It can be made a day in advance and kept in the refrigerator. Bring to room temperature before rolling out.
3. While the dough rests, prepare the béchamel sauce. Place a medium saucepan over low-medium heat and melt the butter. Once it's melted, add the flour using a whisk to avoid lumps. Stir for a few minutes, whisking constantly to cook out the raw taste of the flour. Next, slowly add the milk, whisking all the while to avoid lumps. Raise the heat to medium-high to bring it to a boil. Once it's thickened enough to coat the back of a wooden spoon, turn off the heat and season well with salt, pepper, and a generous amount of freshly grated nutmeg. You can make this a day or two in advance and store it in the fridge. 
4. Next, bring a large pot of water to a boil and add salt. Preheat the oven to 200 C/400 F (if possible, use a ventilated oven). 
5. Roll out your dough. If you know how to do it by hand with a rolling pin, roll it out until thin. Fold it in half to mark the center and cut the circle of dough in half with a sharp knife. You will end up with two large half moon sheets of pasta.
6. If using a pasta machine, divide the dough into 6 equal pieces, covering those not in use with plastic wrap or a bowl to seal out the air which would form a crust. Flatten each piece, sprinkle lightly with flour, and roll into an oval with a rolling pin to the thickness of the #1 setting and the width of the cylinders. Next, run the piece once through each setting in order without skipping a number, until you achieve the thickness desired, adding flour as necessary to prevent sticking. Handle with care and roll the sheet out thinly but not too thin, (to number 6 or 7 on a Marcato Atlas). Proceed with the other pieces. 
7. Once all of the pasta is rolled out, set a large bowl of salted ice water next to the stove and get some tongs and a skimmer ready to help you quickly blanch the pasta. Line a table or counter with clean kitchen towels. 
8. Blanch each sheet of pasta until they float to the surface of the water. This should take under 30 seconds. (If you roll the pasta out thicker than I have indicated, blanch for 30 seconds more after the pasta floats.) To prevent sticking, ease each sheet into the water slowly. Once the pasta is ready, gently remove it from the water and shock it in the bowl of salted ice water. Remove the sheet wringing it out very gently and place it on the kitchen towels. Pat dry. Proceed until you have blanched and lightly dried all of the pasta sheets. (If the pasta tears,  don't worry, it will be rolled up and no one will know!)
9. Spread a layer of béchamel sauce onto each sheet of pasta to nearly the edge. Next, place alternating pieces of ham and mortadella in a single layer. Then, do a layer of the two cheeses, also alternating, placing them next to each other so that the flavor is varied yet not too much. Lastly, sprinkle a layer of Parmigiano Reggiano cheese.
10. Once you have completed filling all of the pasta, roll each sheet up into a log. (If using hand-rolled pasta, roll up each half-moon pasta sheet from the round edge towards the straight edge. You will end up with one long log per half with approximately 13-15 roses per log.) You can wrap the logs in plastic wrap a day in advance if you wish, before cutting. When ready to assemble, cut each log into 5 cm (2-inch) pieces. If your log is very thick, cut them shorter if you wish, about 4 cm (1 1/2-inches). 
11. Place a layer of béchamel sauce in the bottom of a 23x33 cm (9x13-inch) baking dish. Next, place the pasta rolls into the pan, cut side up so that they look like roses. You should have about 24-30 roses depending on the thickness. You can piece the end pieces together to form one rose so as not to waste anything. 
12. Top evenly with the rest of the béchamel sauce and Parmigiano Reggiano cheese to taste. Bake until bubbly and golden, about 25-30 minutes. Let sit for at least 15 minutes before serving.