Heat the olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet and cook until browned, breaking it into small crumbles with a wooden spoon.
Drain any excess fat from the skillet and transfer the beef into the slow cooker.
Finely dice the onion and bell pepper, and mince the garlic.
Add the diced onion, bell pepper, garlic, kidney beans, and diced tomatoes to the slow cooker.
Pour in the beef broth and sprinkle the chili powder, cumin, sea salt, and black pepper over the mixture.
Stir all ingredients thoroughly to ensure the spices are evenly distributed.
Cover and cook on low for 6 to 8 hours, or on high for 3 to 4 hours, until the vegetables are tender and the flavors are well developed.
Stir once more before serving warm in a bowl.