Step 1
Saute pancetta in a large stockpot over medium-high heat until fat has rendered 1 to 2 minutes. Add carrot celery onion and oil. Cook and stir until vegetables have softened and onion is translucent about 5 minutes. Add beef and pork. Cook stirring and mashing meat into small crumbles until browned 5 to 7 minutes more.
Step 2
Stir wine into the stockpot and bring to a boil. Add tomato sauce and stir; pour in 1 cup broth. Reduce heat to low and partially cover the pot to allow steam to escape. Simmer sauce for 1 hour stirring occasionally.
Step 3
Pour 1 more cup of broth into the sauce. Continue simmering until thick 1 to 1 1/2 hours. Add more broth only if absolutely necessary; ragu should drop not run off a spoon.
Step 4
Start preparing pasta after sauce has been cooking for 1 1/2 hours. Bring water and salt to a boil in a small saucepan. Add spinach and cover until it returns to a boil. Stir gently and cook until spinach is heated through. Remove from heat leave covered and let cool.
Step 5
Drain spinach in a mesh strainer set over a bowl pressing it down with a fork to squeeze out as much water and possible; reserve the liquid. Puree spinach in a blender until smooth.
Step 6
Sift flour into a bowl. Make a well in the center; add eggs spinach and about 1 tablespoon of the reserved liquid. Mix together by hand or using the dough hook of a stand mixer adding more liquid if needed. Knead until dough becomes a smooth ball. Cover with plastic wrap and let sit at room temperature for 30 minutes.
Step 7
Taste the ragu and adjust salt. Remove from heat and add milk; stir well and set aside to cool.
Step 8
Divide pasta dough into 4 equal sections. Use a pasta machine or rolling pin dusted with flour to roll pasta into 1/16-inch thick sheets. Lay sheets on clean dish towels to help them dry. Let rest for 20 minutes.
Step 9
Meanwhile melt butter in a saucepan over medium heat. Do not allow it to brown or burn. Add flour and whisk constantly until golden. Add 1/2 cup milk whisking constantly. Repeat with remaining milk. Simmer until bechamel is thickened about 10 minutes. Season with nutmeg and salt.
Step 9
Preheat the oven to 350 degrees F (175 degrees C).