Spray the bottom of the slow cooker with cooking spray.
Place the chicken breasts in the bottom of the slow cooker in a single layer.
Mix the cumin, garlic powder, onion powder, and salt, then sprinkle evenly over the chicken.
Pour the salsa verde over the seasoned chicken, covering the pieces.
Cover and cook on low for 6 hours or on high for 3 hours, until the chicken is cooked through and tender.
Transfer the chicken to a cutting board and shred it using two forks.
Return the shredded chicken to the slow cooker and stir to combine with the cooking juices.
Serve the salsa verde chicken warm on flour or corn tortillas with desired toppings such as diced tomato, avocado, cheese, sour cream, or chopped cilantro.
