Heat a griddle over high heat and slightly char the tomatoes, tomatillos, onion, and dry chilis. In a small skillet toast the pepita and sesame seeds until golden. Set aside.
Remove the seeds from the roasted chilies and soak them in hot water for about 10 minutes. Transfer to the blender. Add the charred tomatoes, onion, cilantro, pepita (pumpkin)and sesame seeds, cinnamon, cloves, salt, pepper, instant corn masa flour (maseca), and chicken broth, and blend until smooth. Set aside.
Bring a large pot of water to a boil and cook the green beans, and carrots for 5 minutes. Add the potatoes and chayote squash, and cook until the veggies are firm-tender. Drain and set the cooked veggies aside.
In the same pot, heat one tablespoon of oil over medium-high heat and brown the chicken pieces on all sides, about 4 minutes. Transfer to a plate.
Heat one more tablespoon of oil in the same pot and cook the sauce for 2-3 minutes.
Return the chicken to the pot as well as the veggies. Bring to a boil, reduce the heat, and simmer for 10 minutes until the chicken is cooked through. Check the seasoning and add more salt if needed.