Heat the vegetable oil in a Dutch oven over medium heat until shimmering. Add onions, bell pepper, and garlic, and cook, stirring often, until softened (about 10 minutes). Stir in chili powder, cumin, coriander, red pepper flakes, oregano, and cayenne, cooking until fragrant (about 1 minute).

Add 1 pound of ground turkey to the pot, increase heat to medium-high, and cook, breaking the meat into small pieces with a wooden spoon, until no longer pink (about 4 minutes). Stir in the kidney beans, diced tomatoes with their juice, crushed tomatoes, and chicken broth. Bring to a simmer.

Reduce the heat to medium-low and cook uncovered for about 1 hour, stirring occasionally, until the chili begins to thicken.

Pat the remaining 8 ounces of turkey into a ball. Pinch off teaspoon-sized pieces of meat, add them to the chili, and stir. Continue simmering for about 40 minutes, stirring occasionally, until the turkey is tender and the chili is slightly thickened. Add more broth if the chili becomes too thick or starts sticking to the bottom of the pot.

Season with salt and pepper to taste. Serve hot with your favorite chili garnishes, such as shredded cheese, sour cream, diced onions, or cilantro.