In a skillet, cook the ground beef with the onion and garlic until the beef reaches 160°F (71°C), then drain the excess fat.
Stir in the broth, beans, chili powder, cumin, salt, pepper, and tomatoes; bring to a simmer.
Simmer for 15 minutes so the flavors blend. Divide the chili into shallow containers and refrigerate promptly until cold.
Pack the cold chili into freezer bags, press out the air, seal, freeze flat, and transport frozen or at 40°F (4°C) or below in an ice-packed cooler.
Thaw in the refrigerator, or in a leak-proof bag submerged in cold water that is changed every 30 minutes. Pour the chili into a pot and reheat to 165°F (74°C), stirring often.