Slow-Cooker Vegetarian Chili

Ingredients

• 1 medium red onion, chopped
• 1 green bell pepper, chopped
• 4 garlic cloves, chopped
• 1 tablespoon chili powder
• 1 tablespoon ground cumin
• 2 teaspoons unsweetened cocoa powder
• ¼ teaspoon ground cinnamon
• kosher salt and black pepper
• 1 28-ounce can fire-roasted diced tomatoes
• 1 15.5-ounce can black beans, rinsed
• 1 15.5-ounce can kidney beans, rinsed
• 1 medium sweet potato (about 8 ounces), peeled and cut into 1⁄2-inch pieces
• sour cream, sliced scallions, sliced radishes, and tortilla chips, for serving