Wash and dry potatoes. Rub a very thin coating of oil over the skins. Prick potatoes with a fork 3-4 times each. Bake in a 400°F oven for 45-55 minutes until fully cooked.
4 whole Russet Potatoes, 1 tablespoon oil
Let potatoes cool enough to handle.
Slice in half lengthwise and scoop out interior. Place in a large bowl. Do not scoop all the way to the skin. You want to leave a thin layer of potato so the skins aren't too flimsy.
Place potato skins on a lightly sprayed baking sheet.
Mash potatoes in bowl. Add butter, sour cream, milk, salt and pepper, Stir.
3 Tablespoons butter, ¼ cup sour cream, ¼ cup milk, ½ teaspoon salt, ¼ teaspoon white pepper
If mixture is too try, add a bit more milk until the mixture is mashed potato consistency.
Fold in cheese, reserving a bit of cheddar for sprinkling on top.
¼ cup shredded Monterey Jack cheese, ¼ cup shredded cheddar cheese, 2 Tablespoons Parmesan cheese
Taste mixture and add additional salt and pepper if needed.
Fill potato skins with potato mixture.
Sprinkle cheddar on top.
Bake at 350 for 20 - 30 minutes until heated through.
Sprinkle with green onions and serve hot
Green onions for garnish
Notes
To make ahead of time, once skins are filled, cover with plastic wrap and store in fridge. When ready to bake, remove plastic wrap and bake at 350 for 30-35 minutes.