In a Dutch oven over medium-high heat, melt the butter; add the onion, cabbage and a large pinch of kosher salt and cook until vegetables begin to break down, 5 minutes. Stir in cider, beer, sauerkraut, ham hock, chili flakes and coriander and simmer, 30 minutes. Nestle in the pork and sausage then continue to simmer until meat is cooked through and tender, 45 minutes.
In a large bowl, whisk together eggs and applesauce. Season with salt, mix in flour and set aside.
Transfer ham hock, pork and sausage to a cutting board. Using fingers or a tablespoon, create small dumplings (they can be a little misshapen) and add to cider mixture; cook until dumplings are cooked through and begin to float; 15 minutes. Mix in parsley and mustard and season with salt and pepper. Cut pork loin and sausage and serve with dumplings and broth.