Filling: Heat oil in a large skillet over medium heat and cook onions 3 to 4 minutes, stirring, until translucent. Add garlic and ground meats and continue to cook over medium heat, stirring frequently. Add the remaining filling ingredients and cook, stirring carefully to avoid the disintegration of the fruit, until the juices have evaporated and the mixture is nearly dry. Transfer to bowl, cover and refrigerate.
Sauce: Pour water into a medium bowl. Add walnuts and soak for 2 hours to rid the nuts of their bitter tannins. Put soaked nuts in a strainer, then transfer to blender. Add almonds, cream cheese, creams, milk, sherry, cinnamon, sugar and salt and blend until smooth. Thin with water if necessary. Transfer to bowl, cover and refrigerate.
Assembly: Preheat the oven to 350°. With small, sharp knife, slit each chile lengthwise, with stems intact, to within 1 inch of bottom. Carefully cut out the seed pod. Rinse the chiles under cold running water to remove remaining seeds. Pat dry with paper towels and put on plate. Grease baking sheet. Stuff each chile with about 1 cup picadillo and close to reshape. Put the stuffed chiles on the baking sheet, cut side up with some of the filling showing. Cover with a loose tent of aluminum foil and bake until heated through, about 25 minutes. While peppers are cooking, halve pomegranate and separate the seeds from the skin. Place the seeds in small bowl. To serve, spoon ½ cup of sauce onto each plate. Lay one stuffed chile atop sauce and scatter 1 tablespoon pomegranate seeds on top. Garnish with parsley sprigs.
From Sarah Rocío Gomez, Executive Chef at Amaranta Cocina Mexicana in Los Angeles