In a large skillet that has a lid, fry the onions in the butter until they are soft and cooked through.Add in the perogies in one layer - I can fit 22-24 in my skillet, depending on size. Place the kielbasa on top of the perogies.Whisk together the cream cheese, sour cream and chicken broth. To prevent curdling of the sour cream, whisk in 1 tbsp of all-purpose flour.If your cream cheese is cold, it will be lumpy - but it will still melt in during the cooking process. Mix in 1/2 cup of cheese and 1/4 cup of the green onions.Pour over the perogies. Place the lid on the skillet and bring to a low simmer over medium heat.Using a wooden spoon, stir occasionally, being gentle and not breaking the perogies, replacing the lid after each stir. Cook for around 10 minutes until the perogies have heated through and are cooked and the sauce has reduced slightly.Remove and top with the remaining cheese and green onions, placing the lid back on to melt the cheese.Serve and enjoy!