Add potatoes and garlic to large stockpot. Cover with cold water until water is least 2 inches over top of potatoes.
Add pot to stove and cook over high heat. Once the potatoes are at a full boil, cook for 30 minutes or until tender.
Drain potatoes. Add to stand mixer fitted with a whisk attachment. Add in butter, sour cream, milk, salt and pepper. Beat on low until butter is mixed in and melted, stopping to scrape sides if necessary. Taste and add more salt and pepper if necessary. Turn up speed to medium-high and whip for 5 to 10 minutes, or until fully whipped.
For the shallots:
Heat 1/2" of oil in a large skillet over medium high heat. Oil is hot enough when a wooden spoon handle sizzles in the oil.
Carefully and slowly add shallots to skillet. Fry for 3-5 minutes, stirring occasionally, or until browned and crispy.
Remove shallots with a slotted spoon and place on a paper towl lined plate. Sprinkle with salt and pepper.
To serve:
Place potatoes on a serving platter.
Top with shallots and parsley.
Notes
I like to reserve the leftover shallot oil for a later use, like searing chicken or to make a stir-fry. It's next level stuff. Just refrigerate it and it'll be good for a couple weeks or so in the fridge.