Heat a large heavy-bottomed pot (Dutch oven) over medium-low heat. Add the olive oil then the onions, peppers, garlic, cumin, salt and ground turkey. Sauté until the turkey is fully cooked.
Add all of the remaining ingredients except for the chips, sour cream and scallions.
Simmer the chili over low heat until the onions and peppers are tender, about 30 minutes. Season to taste with salt and pepper.
When ready to serve, top the chili with sour cream, cheese and scallions.