Drain and rinse beans; set aside. Dice onion and pepper; cut squash into cubes (if not already purchased this way).
In a large stock pan, heat oil over medium heat. Add chopped veggies and cook for 5 minutes, allowing them to soften while stirring occasionally.
Stir in crushed tomatoes, black beans, stock, cumin, chipotle sauce, and pumpkin (if a hotter chili is desired, chop a chipotle pepper from the can and add it as well). Mix well and simmer for 10-15 minutes until veggies are softened.
Top each portion with avocado slices, and serve tortilla chips and pineapple on the side.