Step 1: Heat the olive oil in a large Dutch oven or other heavy pot over medium-high heat. Add the onion and cook for 2 minutes, until the onion starts to soften.
Step 2: Add the ground beef and cook, crumbling, until browned, about 5 minutes. Drain off any excess grease. Add the garlic and cook, stirring, for 30 seconds until fragrant.
Step 3: Add the chili powder, cumin, brown sugar, oregano, salt, pepper, and tomato paste. Stir well to combine, cooking for 1 minute to toast the spices and caramelize the tomato paste.
Step 4: Add the beef broth and stir, scraping up any browned bits from the bottom of the pot to incorporate all the flavor.
Step 5: Stir in the crushed or diced tomatoes and the rinsed and drained beans (kidney and pinto/black).
Step 6: Bring the chili to a boil, then reduce the heat to low and cook at a low simmer for 1-2 hours, stirring occasionally. Cover the chili during the first part of the cook time and then uncover during the last 30 minutes, or as needed, to thicken the chili to your desired consistency.
Step 7: Serve hot with your desired toppings, such as shredded cheddar cheese, sour cream, avocado, and fresh cilantro.