"Here's my version of veal and pork bratwurst. Although this fresh sausage recipe is time-consuming to make, it's the best! You can lower the fat content by adding the optional raw potato. This method is for a food processor, but you can also use a meat grinder. You can also stuff the mixture into sausage casings."
Cut the pork butt, veal, and fat into 1 inch cubes. Spread on a plate, and place in the freezer for 10 minutes to make it easier to chop. Place food processor bowl and blade in the freezer as well for the same amount of time.
Set up the food processor and add just enough meat to cover the blade. Pulse to form chunks about 3/8 inch in size. Repeat with remaining meat. Process the fat into smaller pieces, about 1/4 inch, and mix it with the meat.
Put the chopped meat and fat into a large bowl. Season with salt and pepper, sugar, mustard and mustard seed, nutmeg, and sage. Pour in cold milk, and add grated potatoes if desired. Mix together with your hands.
Make a small patty of the sausage mixture, and fry it in a small pan over medium heat. Taste, and adjust seasonings of the sausage mix if necessary. Cover bowl, and refrigerate for 8 hours to improve flavor before cooking as desired.