In a large skillet, heat the olive oil over medium-high heat. Add the onion and pepper, cooking and stirring until they're tender. Add the garlic, and cook for one minute longer.
Transfer the mixture to a 5-quart slow cooker, then stir in the beans, pumpkin, tomatoes, chicken broth, turkey, parsley, chili powder, cumin, oregano and salt. Cook the chili, covered, on low for four to five hours. Before serving, top each bowl with avocado and green onions, if desired.
