Heat the extra virgin olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet and cook until browned and fully cooked through, breaking it into small crumbles with a spatula.
Drain any excess liquid or fat from the skillet and transfer the browned beef into the slow cooker.
Add the kidney beans, tomato puree, diced tomatoes, diced onion, and diced bell pepper to the slow cooker.
Sprinkle the chili powder, ground cumin, garlic powder, sea salt, and black pepper over the ingredients.
Stir everything together until the spices are evenly distributed and the beef is well coated.
Cover the slow cooker 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 have melded.
Stir the chili once more before serving warm in a bowl.