Melt the butter in a large skillet over medium-high heat. Add the onion, garlic, and shredded kale. Sauté until softened and starting to brown, about 8 - 10 minutes, stirring frequently.
Reheat the mashed potatoes while the veggies are sautéing. This can be don’t on the stove or in the microwave.
Combine the kale mixture with the heated potatoes, cream cheese, green onions, and parsley. Be sure not to over mix. Season with salt, and pepper, if needed.