Heat 1 tablespoon of olive oil in a large pot over medium heat.
Add chopped onion and diced bell pepper; cook until softened, about 5 minutes.
Stir in minced garlic and cook for another minute until fragrant.
Add ground beef, breaking it apart with a spoon; cook until browned.
Drain and rinse kidney beans; add them to the pot along with diced tomatoes.
Add chili powder, cumin, salt, and black pepper; stir to combine.
Pour in the beef broth; stir well and bring to a simmer.
Lower the heat and cover; let chili simmer for 30 minutes, stirring occasionally.