Heat olive oil in large heavy-bottomed pot over medium-high heat. Add diced onions and sauté until translucent and softened, about 5 minutes. Stir in minced garlic and diced bell peppers, cooking until fragrant, about 2 minutes.

Add ground beef to the pot, breaking it up with a wooden spoon into small crumbles. Cook until completely browned with caramelized edges and no pink remains, about 8-10 minutes. Don't rush this step – proper browning creates incredible depth of flavor.

Add chili powder, cumin, smoked paprika, oregano, and cayenne pepper directly to the browned beef mixture. Stir constantly for 1 minute to toast the spices and release their aromatic oils. This step transforms ordinary spices into flavor powerhouses.

Stir in diced tomatoes with their juice, tomato sauce, and beef broth. Bring mixture to a rolling boil over high heat, then reduce heat to low for a gentle simmer. Scrape any browned bits from bottom of pot for extra flavor.

Add drained kidney beans and pinto beans to the pot, stirring to combine. Simmer uncovered for 45-60 minutes, stirring occasionally, until chili reaches your desired thickness. The longer it simmers, the more the flavors meld together.

Taste and adjust seasonings with additional salt, black pepper, or chili powder as needed. Remove from heat and let rest for 10 minutes before serving to allow flavors to settle and deepen.