Taste the sauce and adjust with a pinch of salt and black pepper if needed. The onion soup mix is already salty, so you may not need much.
Serve the hot creamy onion chicken with plenty of the thick, beige gravy-style sauce spooned over mashed potatoes, rice, or noodles. Keep the slow cooker on WARM during dinner so everyone can come back for seconds.
For picky eaters, you can use cream of chicken soup for a milder flavor and cut the chicken into bite-size pieces before cooking so it feels more like a familiar chicken-and-gravy dish. If you like a little extra creaminess, stir in 2 to 4 tablespoons of sour cream or plain Greek yogurt at the very end of cooking (after turning off the heat) for a slightly tangier, richer sauce. To stretch the meal for a crowd, add an extra can of cream soup and a splash of milk, then serve over a big pot of rice. If your family enjoys mushrooms, scatter a cup of sliced fresh mushrooms over the chicken before adding the soup mixture. For a bit of color, stir in a handful of frozen peas during the last 20 minutes of cooking, or sprinkle chopped fresh parsley over the finished dish. You can also swap in boneless, skinless chicken thighs for an even more tender result; just cook on LOW for about 5 to 6 hours. If you prefer a thicker, almost gravy-like sauce, leave the lid off the slow cooker for the last 20 to 30 minutes on HIGH to let some of the liquid evaporate and the sauce reduce slightly.
