Place cubes of chicken in the bottom of a 5 quart or larger slow cooker.
Dump the diced onion on top of the chicken.
Place the cubes of cream cheese around and on top of the chicken and onion.
In a medium mixing bowl mix together the cream of chicken soup, dry Italian dressing mix and garlic powder and pour over everything in the slow cooker.
Cover and cook on LOW for 6 hours.
With a slotted spoon scoop out the chicken and use a wire whisk to mix the sauce mixture to get the sauce to even out as the cream cheese may still be a little clumpy. Mix the chicken back into the sauce.
Serve over pasta or rice and enjoy!
Notes
Using a Crock-Pot Liner makes clean up easier. Totally optional but I recommend it! Prepare your pasta (I used spaghetti) on the stove-top about 20 minutes before the cooking time according to the package directions. If serving over rice (white or brown) make that about 30-45 minutes on the stove-top or in your rice cooker.