Easiest Slow Cooker Chicken and Wild Rice



1 and ½ pounds boneless, skinless chicken thighs (you can substitute chicken breasts if you prefer)
2 (10.75 ounce) cans condensed cream of chicken soup
¾ cup milk
¼ cup marsala wine (optional, just add more milk if you don't have this on hand)
¾ cup frozen chopped onion (can use fresh onion if you have time to chop!)
1 (6 ounce) package long grain and wild rice with seasoning packet (I use Uncle Ben's Original Recipe)