Step 1: Season the chicken and build the base - Place the chicken breasts in the bottom of a six quart slow cooker. Sprinkle the salt, black pepper, and garlic powder right over the chicken, then add the diced onion, butter, and minced garlic. Pour in the chicken broth, followed by the cream of chicken soup, cream of celery soup, poultry seasoning, and dried thyme. Give the sauce ingredients a gentle stir around the chicken so everything is combined without needing to move the chicken around too much. This part is simple, and that is the beauty of it. You are building the whole cozy base right there in the slow cooker, so later you only have a few finishing steps left.
Step 2: Let the slow cooker do the heavy lifting - Cover the slow cooker and cook on low for five to six hours or on high for three to four hours. You are looking for chicken that is tender enough to pull apart easily with two forks. The exact timing can vary a little depending on your slow cooker and the thickness of the chicken breasts, so do not worry if yours needs an extra few minutes. By the time it is ready, the kitchen should smell like a warm chicken dinner has been quietly working away all afternoon. That smell alone usually gets everyone asking when dinner is going to be ready.
Step 3: Shred the chicken into tender pieces - Carefully lift the cooked chicken out of the slow cooker and place it on a cutting board or plate. Use two forks to shred it into bite sized pieces. You do not need perfectly even shreds here. A few larger tender pieces are actually nice in the finished pasta because they make every bowl feel hearty. Return the shredded chicken to the slow cooker and stir it gently into the sauce. It should already look thick and creamy, but the next ingredients will make it even more comforting.
Step 4: Melt in the vegetables and cream cheese - Add the frozen mixed vegetables and cubed cream cheese to the slow cooker. Cover it again and cook for another twenty to thirty minutes, until the vegetables are hot and the cream cheese has melted into the sauce. Give everything a good stir near the end so there are no little pieces of cream cheese left behind. The cream cheese is what gives this pasta that extra velvety finish. It makes the sauce cling to the noodles later instead of sliding right off them, which is exactly what you want with a dish like this.
Step 5: Cook the egg noodles separately - While the vegetables and cream cheese finish in the slow cooker, cook the egg noodles according to the package directions until they are just al dente. That means tender, but still with a little bite in the middle. Drain them well once they are done. Cooking the noodles separately is a small step that makes a big difference. It keeps them from getting too soft in the slow cooker and gives you a much better texture when dinner hits the table.
Step 6: Finish the pasta and let it settle - Add the drained egg noodles to the slow cooker along with the heavy cream. Stir slowly and gently until the noodles are coated in the creamy chicken pot pie sauce. Cover and let everything cook together for about ten more minutes. Before serving, let the pasta sit for five minutes with the lid off. The sauce will thicken just a little more as it rests, and that gives you those creamy spoonfuls everybody loves. Sprinkle chopped parsley over the top and bring the whole slow cooker insert right to the table if your family is anything like mine.