In a large bowl, combine the melted butter, minced garlic, Parmesan cheese, Italian seasoning, salt, black pepper, and red pepper flakes. Mix well to create a garlic Parmesan sauce.
Place the halved baby potatoes in the bottom of the crockpot. Pour half of the garlic Parmesan sauce over the potatoes and stir to coat.
Arrange the chicken thighs on top of the potatoes. Pour the remaining garlic Parmesan sauce over the chicken, ensuring it is well coated.
Cover the crockpot and cook on low for 6-7 hours or on high for 3-4 hours, until the chicken is cooked through and tender.
Once cooked, garnish with fresh parsley before serving.