Lightly spray a 6 quart crock pot with a non stick spray.
Place onions in bottom of crock pot and then top with chicken breasts.
Sprinkle cumin and red crushed peppers on top of chicken then pour hatch salsa over the top.
Cover and cook on high for 5-6 hours or on low for 10-12 hours.
Shred, continue cooking for another half hour. Use for tacos, burritos, nachos or eat with rice and beans or mashed potatoes.