In a large skillet over medium heat, cook the ground beef, breaking it up, until fully browned; drain any excess grease.
Add taco seasoning and the amount of water called for on the seasoning package to the browned beef; stir to coat evenly.
Transfer the seasoned beef to a 6-quart slow cooker.
Add the salsa, drained corn, drained and rinsed black beans, and beef broth to the slow cooker; stir to combine.
Stir in the frozen cheese tortellini so they are evenly distributed, cover the slow cooker, and cook on low for 2½ hours, stirring once each hour.
Sprinkle the shredded cheese over the top, cover, and let sit about 5 minutes until the cheese melts.
Serve warm topped with sour cream and chopped fresh cilantro.