Vegetarian Squash Chili

Name: Vegetarian Squash Chili
Ingredients: 1 tablespoon olive oil; 1 medium red onion; 1 1/2 cups bell peppers; 2 celery stalks; 1 butternut squash; 4 small garlic cloves; 1 tablespoon chili powder; 2 teaspoons ground cumin; 2 teaspoons unsweetened cocoa powder; 1-2 tablespoons chopped chipotle in adobo, depending on how spicy you want your dish to be; 28 ounces can of diced tomatoes; 5 cups cooked black beans; 4 cups vegetable broth (for a richer flavor, replace 1 cup of vegetable broth with 1 cup of brewed coffee); Salt and black pepper to taste; Sour cream, minced chives, and lime wedges for serving