Place the chicken breasts in the bottom of a slow cooker. Season with salt and pepper.
In a medium bowl, combine the black beans, corn, diced tomatoes (with their juices), taco seasoning, and salsa. Mix well.
Pour the bean and corn mixture over the chicken in the slow cooker.
Cover and cook on low for 6-7 hours or on high for 3-4 hours, until the chicken is cooked through and easily shreds with a fork.
Once cooked, shred the chicken in the slow cooker using two forks and mix it with the other ingredients.
Sprinkle the shredded cheddar cheese on top, cover, and let it sit for an additional 10 minutes to melt the cheese.
Serve warm, garnished with fresh cilantro if desired.