In a large pot or Dutch oven, brown the ground beef over medium-high heat. Drain off any excess grease.
Add the chopped onion and cook until softened, about 5 minutes.
Stir in the minced garlic and cook for 1 minute more until fragrant.
Add the crushed tomatoes, kidney beans, pinto beans, and green chilies.
Stir in the chili powder, cumin, oregano, salt, and pepper.
Bring the chili to a simmer, then reduce heat to low, cover, and cook for at least 1 hour, stirring occasionally. For deeper flavor, simmer for 2-3 hours.
Serve hot with your favorite toppings.
Notes
For a spicier chili, add a pinch of cayenne pepper or a diced jalapeño with the onions.
If you prefer a thicker chili, you can simmer it uncovered for the last 30 minutes of cooking.
This chili freezes well, making it great for meal planning.