Boil potatoes until tender, 15 minutes. While the water boils and when the potatoes are cooking, you can be working on the meatloaf recipe.
When the potatoes are tender, drain them and return them to the hot pot to let them dry out a bit. Mash potatoes with half-and-half or milk using a potato masher. Add in the cream cheese and smash until the cheese melts into the potatoes. Then add chives and scallions and season with salt and pepper, to your taste.