For the chicken:
1 cup chicken stock or water
5 cloves garlic, smashed
1 tablespoon ground cumin
2 tablespoon chili powder
1 tablespoon smoked paprika
2 teaspoons kosher salt
2 bay leaves
4 large boneless, skinless chicken breasts (about 2 pounds)
Place the stock or water, garlic, cumin, chili powder, paprika, salt, and bay leaves in the bowl of a 4-quart or larger slow cooker and stir to combine. Add the chicken breasts.
Cover the slow cooker with the lid. Cook until the chicken is tender and registers an internal temperature of 165°F, on low for 4 to 5 hours or on high for 2 to 3 hours.
While the chicken is still warm, transfer it to a cutting board or large plate and use 2 forks to shred the meat.
Divide the meat between the tortillas. Top with guacamole, pico de gallo, and fresh cilantro. Serve immediately.