Heat olive oil in a large non-stick skillet over medium-high heat. Add onion and saute for 3 minutes. Then add garlic and saute for 30 seconds. Pour onions and garlic into 6-7 quart slow cooker.
Then, return the skillet to medium-high heat and add ground turkey and cook until the turkey has cooked all the way through, and it is no longer pink. Make sure to break up the ground turkey as it cooks.
Next, add the browned ground turkey to the slow cooker. There will not be much fat because turkey is lean, but you can drain the fat if you prefer or add it to the slow cooker for additional flavor.
Stir in the diced tomatoes with green chilies, tomato sauce, kidney beans, chili powder, cumin, paprika, sugar, coriander, and add salt and pepper to taste.
Then cover the slow cooker with the lid and cook on low heat for 5-6 hours.
Serve the slow cooker turkey chili warm. Add additional toppings such as shredded cheddar cheese, sliced green onions, or sour cream.