Brown the beef & aromatics: In a large heavy-bottomed Dutch oven or stockpot, heat 1 tablespoon olive oil over medium-high heat. Add the diced onion and bell pepper; sauté for 4 minutes until softened. Add the minced garlic and ground beef, breaking the meat into small pieces with a wooden spoon until browned (about 6-7 minutes). Drain excess fat if desired.

Bloom the spices & tomato paste: Push meat to the sides to create a small well in the center. Stir in 2 tablespoons tomato paste, chili powder, cumin, smoked paprika, oregano, cocoa powder, salt, and pepper. Toast in the hot fat for 90 seconds until deeply fragrant.

Simmer to thick perfection: Pour in the fire-roasted crushed tomatoes, beef broth, drained kidney beans, and black beans. Bring the pot to a vigorous boil, then reduce heat to low. Cover loosely with a lid and simmer for 35 to 45 minutes, stirring occasionally, until thick and luscious.

Rest and garnish: Remove from heat and allow the chili to rest for 5 to 10 minutes (it thickens beautifully as it settles). Ladle into warm bowls and top generously with sharp cheddar cheese, sour cream, and fresh green onions.