Place the chicken breasts or thighs into the bottom of your slow cooker in a single layer.
In a small bowl, whisk together the chicken broth, bouillon, lemon juice, and lemon zest. If using mushrooms, stir them in now. Pour this mixture over the chicken.
Step 2: Season and Add Garlic Butter
In a separate bowl, combine the Italian seasoning, garlic powder, onion powder, paprika, red chili flakes or cayenne, salt, and pepper.
Sprinkle the seasoning blend evenly over the chicken.
Top with minced or sliced garlic and evenly distribute the diced butter on top.
Step 3: Slow Cook the Chicken
Cover and cook on HIGH for 3–4 hours or LOW for 6–8 hours, depending on your slow cooker model and desired texture.
Step 4: Add the Cream Sauce
About 1 hour before the cooking time ends, carefully remove the chicken to a plate. In a small bowl, whisk together the heavy cream and cornstarch until smooth.
Whisk the cream mixture into the crock pot, making sure it’s well combined with the cooking liquid.
Return the chicken to the crock pot, nestling it gently into the sauce. Cover and continue cooking for the final hour.
