Heat 1 tablespoon oil in a large pot over medium heat. Add the onion, bell pepper, and jalapeño with a pinch of salt. Cook, stirring occasionally, for 12-15 minutes, until very soft and lightly caramelized around the edges. (Big flavor-building step.)
Add the ground turkey to the pot. Break it apart with a wooden spoon and cook for 5-7 minutes, stirring occasionally, until cooked through and no longer pink and most of the moisture has cooked off.
Stir in the garlic and cook for 30 seconds to 1 minute, until fragrant.
Push the turkey and veggies to one side of the pot, leaving a clear spot on the bottom. Add the remaining 2 tablespoons oil to the empty side, then sprinkle in the chili powder. Stir the chili powder in the oil for about 30 seconds, just until very fragrant - don’t let it burn - then stir it into the turkey mixture. (Another big flavor-building step.)
Stir in the fire roasted tomatoes, beans, cumin, chili flakes, and a splash of hot sauce. Add broth or water if you need to loosen it to your preferred chili consistency.
Bring to a gentle simmer, then reduce the heat to low. Cook the chili for at least 1 hour, stirring occasionally, until thickened and deeply flavorful. Add a splash of water or broth if it gets too thick. Taste and adjust salt and seasonings as desired.
Ladle into bowls and serve with your favorite fixings.