Prep the base: Lay the sliced onion in the bottom of the slow cooker.
This creates a flavor bed and keeps the chicken elevated so it cooks evenly.
Season the chicken: Add the chicken on top. Sprinkle with cumin, chili powder or smoked paprika (if using), salt, and pepper. Add the minced garlic.
Add the salsa verde: Pour the salsa verde over the chicken.
If you like extra heat or depth, add the diced green chiles here. Stir gently to coat.
Cook low and slow: Cover and cook on LOW for 4–6 hours or HIGH for 2.5–3.5 hours, until the chicken is tender and shreds easily with two forks.
Shred and brighten: Remove the chicken to a cutting board and shred. Stir the lime juice into the slow cooker, then return the chicken and toss to coat.
Taste and adjust salt and pepper.
Optional mix-ins: Stir in black beans or corn for a heartier filling. Let it warm through for 10 minutes on LOW.
Serve your way: Pile into tortillas, spoon over rice, or layer onto salads. Top with cilantro, avocado, a squeeze of lime, and your favorite creamy element.