Place the chicken breasts in a slow cooker and sprinkle with chili powder, cumin, garlic powder, onion powder, salt, and black pepper. Add 1/2 cup of water or chicken broth.

Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the chicken is cooked through and easily shreds with a fork.

Once cooked, remove the chicken from the slow cooker and shred it using two forks. Return the shredded chicken to the slow cooker and mix it with the juices.

Warm the corn tortillas in a skillet over medium heat for about 30 seconds on each side.

Fill each tortilla with shredded chicken, then top with lettuce, tomatoes, cheese, sour cream, and cilantro.

Serve with lime wedges on the side.