In the bowl of the crock pot, combine squash, onion, bell pepper, jalapeño, salsa and broth; give it a stir.
Add the cumin, oregano, garlic powder, black pepper, and stir again so everything is well-combined.
Place chicken breasts on top and submerge so they are fully coated.
Cover the crock pot; cook, on high setting, for 4 hours or low setting for 8 hours.
Thirty minutes before it's finished, remove the chicken to a plate and set aside.
Stir in the beans and replace the lid; let the beans simmer in the sauce while you shred the chicken.
On a plate, using two forks, shred all of the chicken breasts and return to the pot.
To provide more room on the plate, add each shredded breast back into the crock pot as you complete it.
Give the contents a really thorough stir, allowing the chicken to sop up all of that liquid and ensuring everything is well-mixed.
Place the lid back on the crock pot and let it continue cooking until your time is complete.
Just before serving, stir in scallions and, if using, the cilantro.
Serve with optional garnishes.
