Gather all ingredients before starting recipe.
Cover 3 whole potatoes in a deep pot, bring to a boil, reduce to a simmer and for 20-25 minutes or until a paring knife slides through potatoes. Drain and let cool.
Pre heat oven to
425 °F Whisk 3 large egg yolks, 1 clove garlic, 3/4 cup heavy cream, 1/4 cup sour cream and 5 tbsp unsalted butter in a large bowl. Season generously with kosher salt and black pepper.
Peel potatoes and press through a ricer, or mix with a fork until all the lumps have been removed. The potatoes should be light and fluffy and not like a paste.
Fold the potatoes gently into egg cream mixture, do not over mix.
Transfer to a baking dish and refrigerate for one hour.
Remove from fridge, and using a spoon, create a scallop pattern on the potatoes.
Bake, rotating once, until golden brown and slightly puffed, about about 40-45 minutes, if refrigerated ahead of baking.