Heat olive oil over medium high heat in a large heavy bottom Dutch oven or stock pot. When oil is hot, stir in the onions and sauté for 3-4 minutes, or until fragrant. Add garlic and jalapeño (optional) to the pot and stir; cook for an additional 1-2 minutes.
Stir in the fire-roasted green chilis, diced tomatoes, chili powder, ground cumin and salt and pepper (I always add some now and add more at the end). Cook for 2-3 minutes, stirring frequently.
Stir in the green enchilada sauce, white beans, black beans and chicken broth. Mix well. Bring mixture to a low boil. Once boiling, carefully add chicken to the pot and cover. Reduce heat to low. Simmer for at least 30 minutes (more time if chicken breast cuts are really thick).
Once the chicken is cooked, carefully remove breasts from the pot and transfer to a clean plate to cool. Add the chopped zucchini, cilantro and cream cheese to the pot, mixing well. Cover and continue to simmer for 5 minutes.
Meanwhile, once the chicken has cooled, shred using two forks (or, your hands). carefully return to the pot and stir. Season with additional salt and pepper, as needed.
Garnish with sour cream, cheese, lime juice, green onions or cherry tomatoes, if desired.