Grind all the meats and place them in a large bowl.
Add the finely chopped onions and garlic.
Fold in the beaten eggs.
Pour in the Cognac.
Add the coarse sea salt, black pepper, and four-spice blend.
Mix thoroughly until the mixture is completely uniform.
Vacuum-seal the mixture and refrigerate for 15 hours.
Sterilization
Fill the sterilized glass jars with the raw mixture (the jars should be pre-scalded in boiling water).
Wipe the rims, fit the sealing rings or lids, and close the jars firmly.
Place the jars in an electric sterilizer at 100 °C and process for 3 hours.
Alternatively, submerge the jars in a large stockpot of water, cover, bring to a boil, and process for the same amount of time.
Notes
Finely chop the meats For a pleasant texture, chop the meats evenly.Let the mixture rest Resting in the refrigerator is essential; it allows the flavors to meld.