Prepare the meat base. In a large mixing bowl, combine the ground pork and chicken. Mix thoroughly to ensure even texture. For the best results, use a food processor to blend the mixture for a smoother consistency. Set aside.

Prepare the aromatics. Heat 1 tablespoon of butter in a skillet over medium heat. Sauté the finely chopped onion and garlic until soft and translucent, about 3-5 minutes. Allow to cool before incorporating into the meat mixture.

Blend the mixture. Add the sautéed onions, garlic, salt, white pepper, nutmeg, mace, and parsley to the meat mixture. Stir thoroughly to evenly distribute the spices and aromatics.

Incorporate the cream and eggs. Gradually add the heavy cream to the meat mixture, stirring continuously to maintain a smooth texture. Add the eggs one at a time, mixing well after each addition. This ensures the mixture binds properly for the sausages.

Chill the mixture. Cover the bowl with plastic wrap and refrigerate for at least 1 hour. This step firms up the mixture, making it easier to work with when filling the casings.

Prepare the casings. Soak the sausage casings in warm water for 20 minutes. Rinse them thoroughly inside and out to remove any salt or impurities. Fit the casing onto a sausage stuffer nozzle.

Stuff the sausages. Fill the sausage stuffer with the chilled meat mixture. Carefully stuff the casings, ensuring there are no air pockets. Twist the casing every 6-8 inches to form individual sausages. Tie the ends securely with kitchen twine.

Cook the sausages. In a large pot, bring water to a gentle simmer (around 80°C or 176°F). Poach the sausages for 15-20 minutes, ensuring the water does not boil. This step cooks the sausages through while maintaining their delicate texture.

Finish the sausages. Heat the remaining butter in a skillet over medium heat. Lightly brown the poached sausages on all sides, about 2-3 minutes per side. This adds a golden crust and enhances the flavour.

Serve and garnish. Plate the Boudin Blanc alongside traditional accompaniments like mashed potatoes, sautéed apples, or a light mustard sauce. Garnish with fresh parsley for an added touch of colour and freshness.