Makes 4 large servings or 8 small ones, with 6 cups of filling and 2 generous cups of sauce.
Walnuts for the sauce:
• 2 cups (7 ounces) walnut halves and pieces, you'll need 36 (about 1 pound) very fresh walnuts in their shells
• OR 48 mature-green walnuts with fruit still attached (about 4 pounds)
For the chiles and pork-and-fruit stuffing:
• 1 pound boneless pork shoulder, cut into 2-inch cubes
• 2 large garlic cloves, peeled and finely chopped
• 1 small white onion, diced
• 8 very large (about 2 pounds) fresh poblano chiles, choose good-looking chiles with their stems intact if possible
• 3 1/2 tablespoons vegetable oil
• 2 generous tablespoons raisins
• 2 generous tablespoons dried mango, candied biznaga cactus or citron, cut into 1/4 -inch dice
• 1 small pear, peeled, cored and cut into 1/4 - inch dice
• 1 small Jonathan or McIntosh apple, peeled, cored and cut into 1/4 - inch dice
• 2 medium fresh peaches (or extra pears or apples), peeled, pitted and cut into 1/4 - inch dice
• 1 ripe, medium-small tomato, seeded and roughly chopped
• 1 teaspoon dried marjoram
• 1/2 teaspoon dried thyme
• 1/2 teaspoon cinnamon, preferably freshly ground Mexican canela
• Salt, about 1 generous teaspoon
• 1/3 cup (about 1 3/4 ounces) silvered blanched almonds.
• 1 ripe, medium-size plantain, peeled and cut into 1/4 - inch dice.
For finishing the sauce:
• 1 to 1 1/2 cups milk
• 1 slice firm white bread, crusts removed
• 1 tablespoon sugar
• Salt, about 1/2 generous teaspoon
• 1 teaspoon dry sherry
• 1/4 teaspoon cinnamon, preferable freshly ground Mexican canela
• 1/2 cup heavy (whipping) cream or Mexican crema
For the garnish:
• 1 pomegranate
• 8 sprigs flat-leaf parsley
1. Peeling the walnuts. If using mature-green walnuts, break away the soft, green, outer layer with your hands. Working with 5 or 6 at a time, crack open the nuts, remove the meats in the largest pieces possible. Drop the walnut pieces into a small pan of boiling water, immediately remove with a slotted spoon to a paper towel, then peel: the thin, brown skin that covers each piece will peel off in fairly large pieces if the nuts are very fresh; use a small pick or pointed trussing needle to help lift the skin out of the crevices. Continue until all are peeled. Store the nuts in a tightly-sealed jar, refrigerated, until ready to use.
2. Cooking and shredding the meat. Place the pork in a medium saucepan, cover with heavily salted water, add the garlic and half of the onion. Bring to a gentle boil over medium heat, skim off any grayish foam that rises to the surface, partially cover and simmer over medium-low until the meat is thoroughly tender, about 1 1/2 hours.
If time permits, let the meat cool in the broth, then remove it with tongs or a slotted spoon and shred it between you fingers or with two forks held back to back. (There will be about 2 cups of meat). Reserve the broth.
3. Roasting the chiles. The open flame method: Place chiles directly over the gas flame or on a medium hot charcoal or gas grill. Roast, turning occasionally, until blistered and blackened on all sides but not soft, about 5 minutes. The broiler method: Lay chiles on a baking sheet set about 4 inches below a preheated broiler. Roast, turning occasionally until blistered and blackened on all sides but not soft, about 10 minutes. Peel the charred skin off the chiles and rinse them if necessary. Make a long slit in the side of each chile and carefully remove the seeds and veins.
4. The stuffing. Before you start cooking, complete all the initial peeling, coring, chopping and so forth of the stuffing ingredients (a little oxidizing of the apples and pears won't spoil the appearance of the dish.)
Heat 1 1/2 tablespoons of the oil in a very large (12 inch) skillet over medium-high. When quite hot, add the remaining half of the onion and shredded pork in a thin layer and cook, stirring frequently, until the mixture is lightly browned, 8 to 10 minutes. Drain off any excess fat.
Stir in the raisins, candied fruit, pear, apple, peach, the tomato, herbs and cinnamon. Measure in 1/4 cup of the reserved broth, mix well, reduce the heat to medium-low, cover the skillet and simmer until the apple and pear are tender (but not mushy) and the flavors are blended, about 10 minutes. Season with salt, usually a generous teaspoon.
While the meat mixture is simmering, heat the remaining 2 tablespoons of oil in a medium-small skillet over medium heat. Add the almonds and fry, stirring nearly constantly, until they are a deep golden color, about 3 minutes; remove with a slotted spoon and cool. Add the diced plantain to the skillet and stir it frequently until nicely browned and sweet, 3 or 4 minutes. Add to the meat mixture along with the almonds. Remove the filling from the heat and let cool uncovered. (There will be about 6 cups).
5. Stuffing the chiles. Stuff the chiles with cooled filling, packing it in well and re-forming them in their original shape. Place on a baking sheet and cover with foil.
6. Completing the sauce. Within a couple of hours of serving, prepare the sauce. Put the peeled walnuts into a blender jar along with 1 cup of milk, the bread, sugar, salt, sherry and ground cinnamon. Blend until a drop of the puree no longer feels gritty when rubbed between your fingers (this will be more successful with the mature-green walnuts); if the mixture should clog in the machine or if only the mixture at the bottom is moving through the blades, add more milk a little at a time, until all the mixture is moving through the blades again. Finally add the cream and blend for just a few seconds; add additional milk if necessary to achieve a medium consistency. Taste for salt and sugar; the sauce should have a slightly sweet edge with just enough salt to bring up the flavor of the walnuts. Set aside at room temperature.
7. Finishing the dish. Half an hour before serving, place the chiles in a 250-degree oven to heat through. Break the pomegranate apart, pick out all the seeds and place them in a small dish.
When you are ready to serve, add a little mike or cream to the sauce if it is thicker than a medium-consistency custard sauce. Place 1 or 2 chiles (depending on how you have chosen to serve them) on each warm dinner plate. Spoon the room-temperature sauce over the warm chiles, generously covering them half away from the stem. Sprinkle the sauce generously with the pomegranate seeds, garnish with the parsley, and serve at once.
COOK'S NOTES: Techniques: Preparing chiles for stuffing: Since the flavors are more delicate here, it is best to devein the chiles to insure they won't be too hot. If you suspect that they are hot, soak them in salted water overnight.
Timing and advance preparation: Start a day or so ahead, peeling the walnuts (allow 1 1/2 to 2 hours); they will keep for a couple days in the refrigerator tightly wrapped. Finishing the dish will require a little less than 2 hours. The chiles may be prepared and the stuffing made a couple of days in advance; store them separately, covered and refrigerated. Complete Steps 5 through 7 shortly before serving; the sauce can gray if prepared too far ahead.