Clean the chicken pieces and place them in a stockpot with boiling water, onion, garlic, and salt, reduce the heat and poach the chicken until tender about 30 minutes. Remove chicken and reserve broth.
Heat 2 pots of water to boiling. Add salt. Add chayote to 1 pot and green beans to the other. Cook each to al dente. Drain. Slice chayote and set both aside.
For the Mole: Clean the anchos and guajillos with a damp cloth, cut them open, remove the seeds and stems, and spread them flat. Roast them on a hot comal or thin skillet. Remove from the skillet and place in a bowl of hot water and soak for 20 minutes.
On the same comal or skillet dry-roast the tomatillos, tomato, onion, and unpeeled garlic, remove the garlic when black spots appear and peel it, and leave the vegetables until blistered and soft.
In a small skillet, lightly roast the black peppercorns, cloves, and cumin until the aroma is released.
Transfer the reconstituted chiles to the blender with enough water to process. Meanwhile, heat 3 tablespoons oil in large pan and pour the chile mixture through a sieve into the hot pan, it is important that all the pieces of chile skin are blended or removed so the sauce will be smooth. Reduce the heat and let it simmer for 8 minutes.
While frying the chile mixture, blend all the roasted vegetables and roasted spices with enough water to puree. Add this mixture to the frying chile paste, let it simmer for about 20 minutes or until it is reduced. Add reserved chicken broth and simmer for 5 minutes. Dilute masa harina in 1 cup water and add to mixture. Let it cook 10 minutes, check for salt. Add the cooked chicken, peeled and sliced chayote and green beans and cook until heated through. Add hoja santa or cilantro.
For the rajas de chile: Make a small slit in each of the chiles, fry them in hot oil, until all sides are blistered. Remove from oil. Let them cool down and remove the skin, discard it along with seed and stems, tear in pieces, and place the strips in a serving bowl, quarter the pearl onions, and add to the chiles along with lime juice, oregano, and salt.
Serve with white rice and hot tortillas along with the rajas de chile.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Iliana de la Vega, El Naranjo Restaurant, Mexico