Peel and chop the potatoes into about 1 inch cubes.
Add the potatoes to a large pot and add water until the potatoes are covered by about an inch.
Bring the pot to a boil, reduces heat too low. Let the potatoes cook uncovered for about 15-20 mins or until the potatoes are soft.
Drain the potatoes and add the butter, milk, sour cream, onion mixture, roasted garlic, salt, and pepper.
Using the potato masher, mashed until smooth.
Serve and enjoy!