Preheat the oven to 350°. Line a 2 quart pate mold or a 9" x 5" x 3" loaf pan with bacon, letting the ends hang over the sides of the pan. Set aside.
In a small bowl, combine the prunes and cognac. Soak for 10-20 minutes.
In a large bowl, combine the veal pork eggs, thyme, rosemary, salt, white pepper, garlic and scallions. Use your clean hands to combine the ingredients evenly.
Add the prunes and cognac to the pork mixture and mix with your hands to combine.
Fold in the pistachios until evenly distributed in the pate mixture.
Transfer the pate mixture to the prepared pan and smooth the top evenly. If there are strips of bacon still hanging over the pan, fold them over the pate.
Place the pate mold into a 13 x 9" pan and place it in the oven. Add 1" of warm water to the pan. Bake for 1 1/2 hours.
Remove the pate from the water bath and let cool to room temperature. Unmold the pate and wrap in plastic wrap. Refrigerate overnight.Place on a platter to serve, or for smaller groups slice one inch pieces of pate and serve with crackers, toasted baguette or crostini.