Heat the 1 tbsp vegetable oil in a large pot over medium-high heat, add the 1.5 lbs ground beef, and cook for 7 to 8 minutes, breaking into crumbles, until no pink remains. Drain excess fat if needed.

Reduce to medium, add the diced onion, and cook for 5 minutes until translucent. Stir in the 4 cloves minced garlic for 1 minute until fragrant.

Add all 8 spices (chili powder through cayenne) to the pot and stir constantly for 60 to 90 seconds to bloom them in the fat.

Pour in the tomato sauce, diced tomatoes, beef broth, and Worcestershire sauce. Bring to a boil, then reduce to low and simmer loosely covered for 30 minutes, stirring every 10 minutes, until thick.

Taste and adjust salt, then ladle into bowls and top with sour cream, shredded cheddar, and sliced green onions.