For the Boudin Blanc Spices:
Toast the spices, grind them, combine them, and set aside the mixture.
For the Boudin Blanc Base:
Put all the meat grinder parts and tools in the freezer. Put all of the pork shoulder and fatback on ice. Clean the pork casings in cold water, rinsing out the insides as well as the outside. Clean all the meat and fat of any sinew and cut it into 1-inch cubes. Grind the lean meat and fat with a fine die, and heat the milk with the shallots, garlic, and thyme until it is flavorful. After the meat is ground, mix in the eggs, egg whites, salt, 4 grams of the Boudin Blanc Spices, the zest of ½ of the orange, and all of its juice. Add ¼ of the pork mixture to a robot coupe and slowly drizzle in ¼ of the milk. Repeat until the mixture is emulsified and be sure to add the milk slowly, so the if emulsification doesn’t break.
To Assemble and Serve:
Encase and tie the sausages. Poach them slowly in water. Sear them to order.