Heat bacon drippings in a large heavy pot over medium heat. Add the beef and cook until browned, breaking it apart as it cooks. Add the chopped onion and garlic, sautéing until softened and fragrant.

Combine oregano, cumin, basil, salt, pepper, chili powder, and paprika in a small bowl. Stir the spice mixture into the meat and onions, coating everything evenly.

Stir in the tomato paste, beef broth, Rotel, tomato sauce, water, and green chilies (if using). Add cayenne pepper if you like a spicier chili.

Bring the mixture to a boil, then reduce the heat to low and simmer uncovered for 1–2 hours. The longer you let it cook, the deeper and richer the flavors become. If the chili gets too thick, add more water or broth as needed.

Spoon the chili into bowls and top with grated cheese, chopped onions, or even sour cream. Serve with cornbread, tortilla chips, or warm flour tortillas for the ultimate meal.