Step 1: Build the Creamy Sauce - Pour the chicken stock into your crock pot, then add the cream of chicken soup, dried thyme, salt, and black pepper. Grab a whisk and mix everything until the soup and stock come together into a smooth, creamy base. It does not have to look completely perfect at this point because the sauce will loosen and blend as it heats, but breaking up the larger lumps now helps everything cook more evenly. I like getting the seasoning into the sauce before the vegetables and chicken go in so every part of dinner has a chance to pick up that savory thyme flavor.
Step 2: Add the Onion, Carrots, and Celery - Add the diced onion, chopped carrots, and chopped celery directly to the sauce. Give everything a good stir so the vegetables are coated and distributed throughout the crock pot. Try to keep the carrot and celery pieces fairly similar in size when you chop them. That small bit of attention at the beginning pays off later because you are less likely to end up with one big crunchy carrot hiding among otherwise tender vegetables.
Step 3: Nestle in the Chicken - Place the boneless skinless chicken breasts into the crock pot and gently press them down into the sauce. You want the chicken surrounded by plenty of that creamy mixture so it stays moist as it cooks. There is no need to brown the chicken first. That is one of the things I appreciate most about this dinner. On a packed afternoon, skipping an extra skillet and another round of dishes feels like a small victory.
Step 4: Slow Cook Until Tender - Cover the crock pot and cook everything on high for 4 hours. Keep the lid closed as much as possible since every peek lets some of the heat escape. Depending on the exact size and thickness of your chicken breasts and the way your slow cooker runs, the chicken may finish a little sooner. It should be fully cooked and tender enough to pull apart easily. Once it reaches a safe internal temperature of 165 degrees Fahrenheit, you can shred or break it into bite sized pieces right in the crock pot and stir it back into the sauce.
Step 5: Stir in the Peas and Corn - During the final 30 to 45 minutes of cooking, add the frozen peas and drained corn. Stir them gently into the creamy chicken mixture, replace the lid, and let them warm through. Adding them near the end keeps the peas from turning dull and mushy and helps the corn hold onto its sweet bite. By this point, the sauce should smell deeply savory, the carrots should be tender, and you will probably have somebody wandering through the kitchen asking when dinner is ready.
Step 6: Bake the Biscuits - While the peas and corn are warming, bake the buttermilk biscuits according to the package directions. I like timing them so they come out of the oven just before we sit down. That way the tops are golden, the centers are soft and steamy, and everybody gets a warm biscuit beside their bowl. There is something about cracking open a fresh biscuit and dragging a piece through that creamy chicken sauce that makes the whole dinner feel extra comforting.
Step 7: Serve It Warm - Spoon the creamy chicken and vegetable mixture into bowls and serve each portion with a warm biscuit. You can leave the biscuit whole, split it open and spoon some chicken over the top, or tear it into pieces for dipping. At our table, everybody tends to handle the biscuit differently, which is half the fun. However you serve it, make sure each bowl gets plenty of chicken, vegetables, and that thick, savory sauce.