Preheat the oven 275°F
Cut bread into 3/4-inch pieces. Spread bread pieces evenly over a rimmed baking sheet.
Bake for approximately 50 minutes until thoroughly dried, rotating the tray and stirring bread cubes throughout the baking process. Take it out of the oven and let it cool. Increase oven temperature to 350°F
Heat the butter in a large Dutch oven or pot over medium-high heat until it melts. Add the vegan sausage, breaking it into fine pieces, and cook for about 8 minutes until it achieves a light browning.
Stir in the onion, celery, garlic, sage, salt, and pepper and keep cooking for about 10 minutes until the vegetables become tender. Then, take it off the heat and mix in half of the vegetable stock.
In a medium mixing bowl, combine the remaining vegetable stock, Just Egg, and 3 tablespoons of parsley, whisking them together until they form a uniform mixture.
While continuously stirring with a wooden spoon, gradually pour this wet mixture into the sausage mixture. Then, add the stuffing mix and gently fold them in until everything is evenly combined.
Pour the mixture into a well-greased 9x13-inch rectangular baking dish. Cover it securely with aluminum foil, then bake for 60 minutes.
Remove the foil and bake for an additional 20 to 25 minutes or until the top turns golden brown. Once done, take it out of the oven, allow it to cool for 5 minutes, sprinkle with the remaining parsley, and serve.