Brown the ground beef in a large skillet over medium-high heat, breaking it into small crumbles with a wooden spoon, 6 to 8 minutes, until no pink remains.

Drain off excess fat, then stir in the onion and garlic and cook 2 to 3 minutes, until the onion turns soft and translucent.

Add the chili powder, cumin, paprika, oregano, salt and pepper, and stir for 30 seconds until the spices smell toasted.

Stir in the tomato paste and beef broth, scraping up any browned bits from the bottom of the skillet.

Transfer everything to a 4 to 6 quart slow cooker.

Cover and cook on low for 3 to 4 hours, or on high for 1.5 to 2 hours, stirring once halfway through, until the mixture is thick enough to hold a mounded spoon shape with no liquid pooling at the edges.

Switch the slow cooker to the warm setting for serving and stir every 30 minutes so the bottom doesn't scorch.

Taste and adjust the salt just before guests start building their own bags.