Season the beef with salt and pepper all over and place in a large ziploc bag. Add the flour and toss in the bag until the beef is well coated with the flour.

In a large 12-inch nonstick skillet, heat 1 tablespoon of the oil over medium heat until hot and rippling. Add the beef in a single layer and brown on all sides (don't cook it all the way through, just let it get a nice golden color on each side). Transfer the browned beef to a 6-quart slow cooker and repeat with the remaining oil and beef. Toss whatever flour is left in the bag over the beef in the slow cooker.

Add the tomato paste to the skillet and cook over medium heat, stirring constantly, for about a minute so the tomato paste sizzles and darkens in color. Stir in the broth, scraping up any browned bits in the bottom of the skillet. Increase the heat and bring the mixture to a simmer. Cook for 1-2 minutes.

Pour the broth over the meat in the slow cooker. Add the tomatoes, onion, garlic, chili powder, oregano, cumin, coriander, salt and pepper. Cover and cook on high for 4 hours.

Stir in the sweet potatoes, cover the slow cooker again and cook until they are tender, 1-2 hours on high. Stir in the chiles, corn, cilantro, lime juice and additional salt and pepper to taste. Let sit for just a minute or two to let the corn heat through (if using frozen).

Serve with lime wedges, if desired.