Brown the ground beef in a large pot or dutch oven over medium-high heat.
Add the onion and garlic and cook until softened.
Stir in the chili powder, cumin, oregano, salt, and pepper.
Pour in the tomato sauce and diced tomatoes.
Add the kidney beans and simmer for 30 minutes to 1 hour, until thickened.
Serve hot, with desired toppings.