Add the oil, 1 cup of scallions and garlic. Sauté about 2 to 3 minutes until soft then add the tomatoes and sauté another minute, until soft.
Add chicken stock, cumin and chile powder and bring to a boil. Simmer, covered on low for about 15 minutes.
In four bowls, fill each with 1/2 cup chicken, 1/2 avocado, remainder of the scallions, and cilantro. Ladle 1 cup chicken broth over the chicken and serve with a lime wedge.