Place the chicken breasts in a slow cooker.
Add diced onion, garlic, tomatoes, chipotle peppers, chicken broth, cumin, paprika, chili powder, salt, and pepper.
Cover and cook on low for 6-7 hours or on high for 3-4 hours until the chicken is tender.
Remove chicken from the slow cooker and shred using two forks.
Return shredded chicken to the slow cooker, stir in lime juice, and cook for an additional 15 minutes.
Garnish with fresh cilantro before serving.