Leaving the peels on the sweet potatoes has three benefits: Prep is faster, you add more fiber, and the potatoes hold their shape better after the 7-hour simmer. Besides, the peels get so tender that you barely notice they're there. If you'd like to change things up, try parsnips in place of the sweet potatoes; they have a similar sweetness and earthier flavor. For less sweetness, you can try small red potatoes or baby Yukon Golds. You don't need to fully cook the ground beef before it goes into the slow cooker; just cook it enough to "set" the shape of the crumbles.
How to Make It
Heat a large nonstick skillet over medium-high. Add beef to pan; cook, stirring often, just until crumbled and mostly browned, about 3 minutes. (Beef will not be fully cooked.) Remove from heat.
Combine sweet potatoes and next 11 ingredients (through black beans) in a 6-quart slow cooker. Stir in beef. Cover and cook on LOW 7 hours. Stir in 1/2 cup cilantro. Ladle chili into 8 bowls; top with cheese and remaining cilantro.