Filling: Coat a large saute pan with olive oil, add the onions and put the pan over medium heat. Season the onions with salt, to taste, and add a pinch of crushed red pepper flakes. Saute until the onions are translucent and very aromatic, about 7 to 8 minutes. Stir in the garlic and saute for 3 to 4 more minutes. Add the pork sausage and cook until nicely browned. Stir in the spinach, season with salt, to taste, and saute until the spinach is wilted, about 2 to 3 minutes. Remove from the heat and let cool. In a large bowl, add the ricotta, 1 cup of grated Parmigiano, the eggs and 1 cup of bechamel and stir to incorporate. Mix in the cooled sausage mixture into the ricotta mixture. Taste and adjust seasoning, if needed. To assemble the manicotti: Preheat the oven to 350 degrees F. Prepare the baking dish by evenly schmearing 1 cup of bechamel sauce in the bottom of a 9 by 13-inch baking dish. Put 2 heaping tablespoons of the filling on a crepe just below the halfway mark. Form the filling into an even log and then roll up the crepe to enclose the filling. Repeat with the remaining filling and crepes. Arrange the crepes in the baking dish , snuggling the crepes together until the dish is filled. Spoon the tomato sauce over the top of the crepes and spread the bechamel in a wide swath down the middle. Sprinkle with the remaining 1/2 cup of Parmigiano and cover with foil. Bake in the preheated oven until heated through, about 30 minutes. Remove the foil and bake until the top starts to brown a little, about 5 to 10 minutes. Remove from the oven and serve topped with a little extra cheese . Mamma mia! Add the butter and onion to a large saucepan over medium heat. Season the onions with salt, to taste, and cook until they become translucent and very aromatic . Add the flour and cook until the flour and butter resemble wet sand, about 3 to 4 minutes. Gradually, whisk in the milk until incorporated. Add the bay leaf and nutmeg and season with salt, to taste. Slowly bring the milk/flour mixture to a boil , stirring frequently to prevent scorching on the bottom. Be sure that the milk comes to a boil or the flour will not cook out and you will be left with a very objectionable starchy feeling on your tongue . Once the sauce has come to a boil and has thickened, remove it from the heat. Discard the bay leaf . Stir in the grated Parmigiano, taste and adjust seasoning, if needed. Use right away or refrigerate, covered, until ready to assemble dish. Creamy! Coat a large sauce pot with olive oil and add the pancetta. Put the pot over medium-high heat and cook the pancetta for 4 to 5 minutes. Add the onions, season generously with salt, to taste, and stir to coat with the olive oil. Cook the onions for 6 to 7 minutes, stirring frequently. The onions should become very soft and aromatic but have no color. Add the garlic and cook for another 2 to 3 minutes, stirring frequently. Pass the tomatoes through the food mill. Be sure to pass all of the pulp through the holes leaving only the stems and the seeds, and be sure to scrape the pulp off of the bottom of the food mill . That's all of the big money stuff! Add the tomatoes to the sauce pot and 1 can of water (about 2 to 3 cups). Season generously with salt and TASTE IT!!! Tomatoes take a lot of salt. Season in baby steps and taste every step of the way. Cook the sauce for 2 to 3 hours, stirring occasionally and tasting frequently. Use the sauce right away on pasta or for any other tomato sauce need. This sauce can also be cooled and stored in the refrigerator for a few days or it can be frozen. Batter: In a mixing bowl, add the flour and salt and make a well in the center. Add the remaining ingredients, except the melted butter, into the center of the well and whisk together until just combined. The mixture should be like VERY loose pancake batter. If the mixture is a little thick, whisk in a little more milk. Let the batter sit for at least 30 minutes before using. *Tip: Crepe batter can be made up to 2 days in advance, covered and refrigerated. Crepes: Melt about a 1/2 teaspoon of butter in a small nonstick saute pan. The butter should coat the bottom of the pan, if there is a lot of excess, wipe it out with a paper towel. Keep the paper towel handy in case you need it again (you will). Put the pan over medium heat. Fill a 2-ounce ladle, almost to the top, with batter and pour it into the preheated pan, tipping and rolling the pan, as you ladle the batter , to evenly cover the bottom. This will take a little practice, even when you are an experienced crepe maker the first couple always get wasted. Accept it and move on. When the edges of the crepe begin to pull away from the edges of the pan and the bottom begins to brown a little, turn the crepe over and cook it for about 1 minute on the other side. Remove the crepe from the pan to a plate and let cool. Stack the crepes as they are cooked between parchment paper squares. Repeat this process, until all the batter is used, wiping the pan with your paper towel or melting a little more butter to the pan, as needed. YAY!