Preheat the oven to 350 degrees F.
Place the serrano chiles and tomatoes on a very hot grill and cook until charred, 12 to 15 minutes. Stem the chiles an add to a blender with the whole garlic clove and blend until smooth.
Saute the remaining 2 garlic cloves and the onions in a skillet until browned, 2 to 3 minutes. Add the pork and cook until no longer pink, 2 to 3 minutes. Add the tomato/chile sauce to the pork mixture and heat through.
Meanwhile, place the poblano chile on the grill until its skin is blackened, 5 to 8 minutes. Remove the skin and seeds, keeping the pepper whole.
Saute half the plantains in a skillet until golden brown, 2 to 3 minutes and then add the pork mixture. Mix in the almonds, raisins and season with salt. Spoon the pork mixture into the poblano chile.
Put the chile in the oven and bake until heated through, 15 to 20 minutes.
Meanwhile, blend the remaining plantains with the heavy cream. Spoon the plantain sauce on the bottom of a plate and top with the chile relleno. Sprinkle with the cilantro over the top and serve.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.