In a stockpot or Dutch oven over medium-high heat, add the oil, garlic and onion. Sprinkle with salt and pepper and saute until the onion gets tender and aromatic, 3 to 5 minutes. Add the tomato paste and stir well. Add the ground beef and cook until browned, stirring frequently and breaking it apart, about 5 minutes. Add the chili powder and cumin and stir until evenly distributed. Stir in the tomato sauce and broth and lower the heat to a simmer. Cook, stirring occasionally, 30 minutes. Stir in the barbecue sauce and cook for an additional 10 minutes. Serve hot.