Season the chicken with 1/2 teaspoon thyme, and salt and pepper to taste; set aside. Heat the vegetable oil in a large saucepan over medium heat. Add the onion, jalapeno and garlic and cook until soft, about 4 minutes. Transfer to a blender, then add the chiles, cilantro and the remaining 1/2 teaspoon thyme and puree until smooth. Return to the saucepan and cook over medium heat, stirring, until the sauce thickens and turns deep green, about 5 minutes. Add the broth, hominy and chicken to the saucepan. Cover and simmer until the chicken is tender, about 10 minutes. Garnish with avocado, radishes and/or corn chips, if desired.