Step 1: Season the chicken - Sprinkle the chicken evenly with salt and black pepper. Place it in an even layer in the bottom of your slow cooker. This gives the chicken a head start on flavor before anything else goes in.
Step 2: Add the vegetables - Scatter the sliced onion carrots celery mushrooms and garlic over the chicken. No need to stir yet. Just let everything settle in naturally.
Step 3: Mix the sauce - In a small bowl whisk together the merlot chicken broth tomato paste Worcestershire sauce Italian seasoning and dried thyme. Take a second to smell it. That is the good stuff.
Step 4: Pour and cook - Pour the sauce evenly over the chicken and vegetables. Cover and cook on low for six to seven hours or on high for three to four hours until the chicken is tender and infused with flavor.
Step 5: Thicken the sauce - In a small bowl mix the cornstarch with cold water until smooth. Stir it into the slow cooker liquid. Switch to high and cook for ten to fifteen minutes until the sauce thickens slightly. Stir in butter if using.
Step 6: Serve and enjoy - Spoon the chicken and sauce over mashed potatoes noodles or bread. Sprinkle with fresh parsley and serve warm.