Heat the oil in a 4-quart cast iron saucepot. Working in batches, add the cubed pork and brown on all sides. Set the browned pork aside. Add the onions and poblano peppers to the saucepot and continue to sauté for a few minutes until the vegetables start to soften. Add the Jalapeño pepper, chili powder, cumin and cinnamon and sauté for an additional minute. Stir in the fire roasted tomatoes and beef stock and bring to a boil. Return the browned pork and any juices back to the saucepot. Lower the heat, cover the saucepot and simmer for 30 minutes, stirring often.

Stir in the pumpkin purée and simmer uncovered for 20 more minutes, until pork is tender.

Season to taste with salt and fresh ground black pepper. Serve the chili in bowls topped with a dollop of sour cream and roasted pepitas seeds sprinkled on top.