For the sausage: In a large bowl, combine the pork, garlic, sage, salt and crushed red pepper. Run the mixture through a meat grinder fitted with the die with the largest holes. Repeat so that all the meat goes through the grinder twice. Add the water and Parmesan and mix together.
Attach the sausage-stuffing attachment to the meat grinder, keeping the grinder blade and die in place. Place a generous amount of the sausage mixture into the grinder pan. Give the casings a slight bit of resistance by holding onto the sausage stuffer with three fingers and letting the casing slip through your thumb and forefinger. Turn the machine on and fill the casings, being careful to avoid any air bubbles.
Twist the casings to create evenly-sized 4-inch sausages. Tie the sausages with butcher's twine to keep them nicely sealed, then prick all over with a pin or skewer to allow steam to escape while cooking (you don't want to have a blow-out!).
Place the sausage links into boiling water and parboil for 10 to 15 minutes. Remove from the water, reserving the sausage water for spätzle, and transfer sausages to a preheated saute pan slicked with oil. Saute until browned, about 6 minutes.
For the spaetzle: Bring the sausage water back to a boil over medium heat.
In a small bowl, whisk together the eggs and milk until homogeneous.
Add the flour to a large bowl and make a well in the flour. Add a pinch of salt and then, with a fork, gradually combine the milk-egg mixture with the flour. Mix until just combined. Stir in half of the dill, marjoram, oregano and parsley (1/4 cup total).
Place the batter in a colander set over the boiling sausage water. Using a rubber spatula or a spaetzle maker, push the batter through the colander and into the water. Boil the spaetzle until firm, 2 to 3 minutes. Drain and add to a preheated saute pan slicked with oil. Add the savoy cabbage, white wine and mustard and cook for 15 to 20 minutes. Finish with the butter.
Serve 2 sausages to a plate with herb spaetzle on the side.