In a large pot over medium heat, brown the ground beef until fully cooked, breaking it apart as it cooks.
Drain excess fat if necessary.
Add chopped onion and minced garlic; sauté until softened (about 5 minutes).
Stir in diced tomatoes with juice and kidney beans, mixing well.
Sprinkle in chili powder and cumin, stirring thoroughly.
Allow to simmer on low heat for about 10 minutes.
Adjust consistency by simmering uncovered for thicker chili or adding water/broth for thinner.
Serve hot, garnished with cheese or cilantro if desired.