Preheat the oven to 400 degrees. Pierce sweet potatoes with a fork and place on a baking sheet. Bake about 1 hour and 15 minutes, or until tender.
Saute bell pepper and onions in a small amount of broth or water over medium heat until soft and golden, about 10 minutes. Add garlic and cook for 2 minutes more. Stir in spices, tomatoes, and beans and bring to boil. Reduce heat, cover, and simmer for 20 minutes.
Add squash and jalapeno. Cook, covered, about 6 minutes or until squash is crisp-tender. Place one peeled, slightly mashed sweet potato on each plate. Top with chili and drizzle with freshly squeezed lime juice, if desired.