Place the tomatillos, onion, garlic, jalapeño, and cilantro in a blender. Add 1 cup of the chicken broth and blend until smooth.
Pour the blended mixture into a large pot over medium heat. Cook for 5 minutes, stirring often, until it starts to bubble.
Add the remaining chicken broth, hominy, salt, and pepper. Bring the soup to a simmer and cook for 10 minutes.
Stir in the shredded rotisserie chicken and lime juice. Simmer for another 5 minutes until the chicken is heated through.
Ladle the soup into bowls and add sliced radishes and diced avocado on top before serving.