Soak the walnuts in the milk while you prep the recipe. Reserve for later
Peel the plantain and dice it fine. Place in a bowl with water until you are ready to use.
Heat 2 tablespoons avocado oil to medium heat for 5 minutes. Add the ground pork and beef. Season to taste with salt and pepper. Cook for about 7 minutes until browned. Add the onion, garlic and drained plantains. Sauté for 5 minutes. Add the tomato and remaining spices. Stir well to combine and cook for 5 minutes or until most of the liquid is absorbed.
Mix in the raisins, and remaining fruit. Stir well to combine. Taste for salt. Turn heat to low and continue cooking for 7 minutes, mostly covered. Remove from heat when ready.
While the filling is cooling prepare nogada sauce. Combine all of the ingredients in the blender. Blend until smooth, taste for salt and sugar, cover and set aside. If the sauce is too thick, mix in a little more milk.
Remove the blistered skins from poblano peppers. Make a slit just below base of pepper about 1/2 inch from the bottom of pepper. Using your fingers, gently remove the seeds, as many as you can from the inside of peppers. Fill each pepper, gently pushing with your fingers to fill each space. Do not over fill. Transfer to a baking dish and keep warm in low temperature oven. To serve add one pepper to a plate. Ladle with walnut sauce. Garnish with pomegranates and parsley.