In a large pot, cover potatoes with water and add a generous pinch of salt. Bring to a boil and cook until totally soft, 16 to 18 minutes. Drain and return to pot.
Meanwhile, make the caramelized onions: In a large skillet over medium-low heat melt butter. Add onion and season with salt. Cook until soft and golden, about 10 minutes.
When the potatoes are tender, use a potato masher to mash until smooth. Add in sour cream and milk and stir until smooth. Fold in caramelized onions and chives and season with onion powder, salt, and pepper. Garnish with chives and serve.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2017/12/20/sour-cream-onion-mashed-potatoes/