Chop the onion and pepper into a small dice. Mince the garlic.
Heat olive oil in a large pot over medium heat. Add the onions, peppers, and garlic and sauté about 3 minutes over medium heat, until they are just tender.
Add the ground turkey and break up with a wooden spoon or spatula while cooking until the meat is no longer pink (about 5 minutes).
Add the diced tomatoes, tomato puree, pinto and kidney beans, chili powder, red pepper flakes, cumin and oregano. Mix well. Bring the mixture to a boil then lower to a simmer and cover with a lid. Allow the mixture to simmer for at least an hour.
Spoon the chili into bowls and top with sour cream and cheddar to your liking.