Grind all the meats and mix them together in a large bowl.
Add the finely chopped onions and garlic.
Stir in the beaten eggs.
Pour the Cognac into the mixture.
Add the coarse sea salt, black pepper and four-spice blend.
Mix everything together thoroughly until evenly combined.
Let rest, vacuum-sealed, in the refrigerator for 15 hours.
Sterilization
Fill the clean glass jars (rinsed with boiling water beforehand) with the raw mixture.
Fit the rubber seal or lid on the jars, wipe the rims and close them.
Place the jars in an electric sterilizer set to 100°C and sterilize for 3 hours.
Alternatively, the jars can be placed in a Dutch oven filled with water, covered and kept at a boil for the same amount of time.
Notes
Grind the meats well: For a pleasant texture, make sure to grind the meats evenly.Let it rest: Don't skip the resting time in the refrigerator. It allows the flavors to blend and develop.