Over an open flame, roast the poblano peppers until all sides are charred. (See additional roasting options below if needed.)
Transfer the peppers to a large bowl and cover with plastic wrap. Let them steam for 10-20 minutes.
After steaming, remove the peppers and peel off the charred skin. (It should slide off easily.) Remove the stems and seeds, then chop the peppers.
In an 8-quart soup pot, heat the olive oil over medium-high heat. Add the chopped onion and sauté until the edges are golden and fragrant, about 3 minutes.
Add the minced garlic to the pot and cook for about 1 minute until aromatic.
Stir in the cumin, coriander, and cinnamon, and let the spices warm for a few seconds until fragrant.
Add the bouillon, salt, pepper, pumpkin puree, black beans, and chicken broth. Stir and heat until the soup is steaming, about 10 minutes.
Once the soup is hot, add the cubed rotisserie chicken. (Adding the chicken last keeps it tender and juicy.)
Reduce the heat and let the soup simmer for 5 minutes.
Serve hot, dividing the soup among bowls. Makes six servings. Garnish with sour cream, more chopped poblano, even a little grated cheddar cheese if desired. Enjoy!