1 tablespoon olive oil
- Heat the oil in a large saucepan over medium heat. Add the onion, garlic, and red pepper. Sauté until fragrant, about 3 minutes.
- Add the ground beef and brown, about 5 minutes.
- Stir in the tomato paste, chili powder, cumin, salt, black pepper, and cinnamon. Simmer, stirring occasionally, until thickened slightly, about 12 minutes.
- Spoon onto the buns. Sprinkle each with the Cheddar and top with a dollop of the sour cream.