Place the chicken breasts in the slow cooker. Add the diced onion, minced garlic, diced tomatoes, black beans, corn kernels, chicken broth, chili powder, cumin, paprika, salt, and pepper.
Stir the ingredients to combine. Cover the slow cooker and cook on low for 6-8 hours or on high for 4-6 hours, until the chicken is tender and easily shreds.
Remove the chicken breasts from the slow cooker and shred them using two forks. Return the shredded chicken to the slow cooker and stir well.
Add the lime juice to the soup and stir to incorporate the flavors.
Ladle the Slow Cooker Mexican Chicken Tortilla Soup into bowls. Top each bowl with diced avocado, a squeeze of lime juice, fresh cilantro, and crispy tortilla strips or crushed tortilla chips.
Serve the soup hot and enjoy the flavors of Mexico in every spoonful.
