Step 1: Heat olive oil in a large pot over medium heat. Add chopped onions and minced garlic, sauté until they are soft, about 5 minutes.
Step 2: Add the ground beef to the pot. Cook it until browned, breaking it up with a spoon, about 8 minutes.
Step 3: Stir in chili powder, cumin, salt, and black pepper. Cook for 2 minutes until fragrant.
Step 4: Pour in diced tomatoes and tomato sauce. Bring to a simmer.
Step 5: Drain and rinse the kidney beans. Add them to the pot. Reduce heat and let simmer for 30 to 60 minutes, stirring occasionally.
Step 6: Adjust seasonings to taste and serve hot.