- In a large pot over medium-high heat, soften the celery, carrots, onion and bell pepper in the oil. Add the turkey and cook, breaking it up with a wooden spoon, until browned. Add the sweet potato, tomatoes, beans, ketchup, mustard and spices. Stir to combine and bring to a boil.
- Cover and let simmer for 30 minutes or until the sweet potato is tender. Season with salt and pepper. Add the cilantro, green onions and lime juice.
- With the rack in the middle position, preheat the oven to 400°F (200°C).
- Spoon the chili into an 11 x 8-inch (28 x 20 cm) baking dish. Sprinkle with the cheese. Freeze at this stage, if desired.
- Bake for 20 minutes (or 45 minutes if frozen) or until the cheese is golden brown.