Step 1: Add the hearty ingredients - Add the leftover turkey, potatoes, carrots, celery, onion, and minced garlic directly into your slow cooker. Give everything a gentle stir so it is evenly distributed.
Step 2: Mix the broth - In a medium bowl, whisk together the turkey broth, turkey gravy mix, poultry seasoning, garlic powder, and onion powder until smooth.
Step 3: Pour and cook - Pour the broth mixture over the ingredients in the slow cooker. Cover and cook on high for 4 hours or low for 6 hours until the vegetables are tender.
Step 4: Thicken the stew - In a small bowl, whisk together the heavy cream and cornstarch until smooth. Stir this mixture into the slow cooker.
Step 5: Add the peas - Stir in the frozen peas, cover, and cook for another 30 minutes until the stew thickens and everything is heated through.
Step 6: Garnish and serve - Taste and adjust seasoning if needed. Garnish with fresh parsley if desired and serve warm.