Slice the venison tenderloin into one-inch-long strips. Marinate overnight with the gin and juniper berries in a plastic container or a zippered plastic bag.
The next day, in a food processor, mix together the shallots, chicken livers, thyme, rosemary, and allspice, and process into a purée.
Mix together the pork, veal, and ground venison in a large bowl. Add the liver mixture and the eggs.
Pour the juice from the marinated strips, including the gin and juniper berries, into the meat mixture. Reserve the strips for later. Salt and pepper the mixture generously. Gently sauté a tablespoon of the mixture to taste test. Pâté must be well seasoned and spiced, as it loses some of its flavor after being cooked.
Preheat the oven to 300ºF. Line a three-pound terrine with the bacon on all sides. Lay one-third of the ground meat in the terrine. Pack tightly by pressing down with your hands. Add the thin strips of marinated venison and the pistachios. Do not create a thick layer—instead push the strips and nuts into the meat. If the meat does not surround the strips and the nuts, the pâté will split when cut. Top with the remainder of the meat.
The terrine should be overfilled, as pate reduces in size after cooking. Cover the ground meat with bacon strips. Top with two bay leaves. Cover with terrine lid or aluminum foil. Set the terrine in a pan of hot water in the preheated oven. Bake for 35 minutes.
Remove lid or foil and bake for another 35 minutes. Check temperature after about 25 minutes. When a meat or instant-read thermometer reaches 160ºF and juices run clear when meat is punctured by the thermometer, the pâté is done. Cooking time varies based on shape of terrine and oven type.
Remove the terrine from oven and lay foil on top. Put at least a half-pound weight on top (a large can will do). Let the pâté cool on the kitchen counter. Make sure the terrine sits on an empty pan, as liquid may spill over the edges. This is an important step in the process as the weight pushes the fat and liquid out of the pâté and creates the coating.
When pâté has cooled, cover it tightly and refrigerate for at least three days. This amount of time is necessary in order to bring out all the flavors from the spices.
Serve at room temperature or cold. Slice and serve on toast, accompanied by French cornichons. Pâté can be kept tightly covered for up to three weeks in the refrigerator.
Variations for duck or rabbit pâté:
in the above recipe, you can substitute strips from the breast of a duck or the tenderloin of a rabbit for the strips of venison. Substitute cognac or Armagnac and peppercorns for the gin and juniper berries. Walnuts or hazelnuts can be substituted for the pistachios. All other ingredients and the cooking time remain the same.