In a large skillet over medium heat, add in the olive oil, ground beef, and onions.
Cook while stirring and chopping until the ground beef is browned and cooked.
Drain juices and add to a slow cooker.
To the slow cooker also add the kidney beans crushed tomatoes, green chilis, and rotel.
In a small bowl, mix your chili powder, cumin, basil, cayenne, pepper and salt. Pour over the other ingredients in the slow cooker, and stir well.
Cook on HIGH for 2 hours, stirring every 30 minutes.
Garnish with sour cream, cheese, or your choice of onions and herbs.
ENJOY!