In a large dutch oven or chili pot, combine onions, garlic & olive oil. Sauté over a low/medium heat until softened and fragrant.
Add ground turkey. Continue cooking until the turkey is about 90% cooked through.
In a separate saucepan, sauté cubed sweet potatoes until they start getting soft.
In a small mixing bowl, combine chili powder, cumin, paprika, nutmeg, cinnamon, salt & pepper. Mix until combined.
Once potatoes are cooked through, add to dutch oven. Then add in crushed tomatoes, chicken broth, corn, black beans and seasoning mixture. Then, add brown sugar & mix until combined.
Reduce heat to low. Cover the pot & let simmer for about 40 minutes, stirring every 10 minutes.
Top with tortilla strips, chopped green onion, sour cream & cheddar cheese.