Heat vegetable oil in a large pot over medium-high heat. Add minced garlic and chopped onion and cook, stirring, until golden, 7 to 9 minutes.
Add chili powder, sugar, and ground cumin. Cook, stirring constantly, 2 more minutes. Add ground beef and cook, stirring, until beef is evenly browned, 5 to 7 minutes.
Stir in tomato paste, beef broth, cornmeal, salt, and bay leaf. Reduce heat to low and simmer until the chili is very thick, 15 to 20 minutes. Discard bay leaf before serving.