Cook the ground meat: In a large pot or Dutch oven, heat the olive oil over medium heat. Add the ground beef (or turkey) and cook, breaking it up with a spoon, until browned and fully cooked, about 5-7 minutes. Drain any excess fat.
- Sauté the onions and garlic: Add the chopped onion to the pot and cook for about 3-4 minutes, or until softened. Add the minced garlic and cook for an additional 1-2 minutes, until fragrant.
- Add the tomatoes and beans: Stir in the diced tomatoes (with their juices), tomato paste, kidney beans, and black beans. Add the beef broth (or water) and stir to combine.
- Season the chili: Stir in the chili powder, cumin, paprika, salt, pepper, and crushed red pepper flakes (if using). Mix well to coat the ingredients in the spices.
- Simmer the chili: Bring the chili to a simmer over medium heat. Once it starts to bubble, reduce the heat to low and let it simmer uncovered for 25-30 minutes, stirring occasionally. The chili will thicken as it simmers.
- Adjust the seasoning: Taste the chili and adjust the seasoning with more salt, pepper, or chili powder if desired.
- Serve: Ladle the chili into bowls and serve with your favorite toppings such as shredded cheese, sour cream, green onions, or chopped cilantro. Enjoy with cornbread or tortilla chips for added texture.