Wash, dice, and mince all vegetables. Measure out all spices to streamline cooking.

Heat olive oil in a large pot over medium heat. Add diced onions and sauté for 3–4 minutes until translucent. Add minced garlic and sauté another 30 seconds until fragrant.

Add diced bell peppers to the pot and sauté for 4–5 minutes until slightly softened but still crisp.

Push vegetables to the side and add ground beef to the center of the pot. Break it up with a spoon or spatula and cook until browned, about 5–7 minutes. Drain excess fat if needed, leaving a tablespoon for flavor.

Stir in diced tomatoes, tomato paste, and beef broth. Mix thoroughly to combine and coat all ingredients evenly.

Add chili powder, cumin, smoked paprika, oregano, coriander, cayenne (if using), salt, and black pepper. Stir well to distribute the spices evenly.

Reduce heat to low and let the chili simmer uncovered for 25–30 minutes. Stir occasionally. The chili should thicken slightly and develop a rich, deep flavor.

If using zucchini or cauliflower, add them during the last 10–15 minutes of simmering to cook without becoming mushy.

Taste for seasoning and adjust salt, pepper, or spices as needed.

Ladle the chili into bowls and top with shredded cheese, sour cream, avocado slices, cilantro, or jalapeños if desired.