1. Heat the oil in a Dutch oven over medium-high heat.
2. Add the onion and garlic; cook 4 minutes, stirring occasionally, until onion is softened.
3. Add the cumin, chili powder, chipotle and beef (if using); cook 5 minutes, stirring to break up the meat, until browned.
4. Add diced and crushed tomatoes and kidney beans; cook until chili is thick, 12 to 15 minutes.