Quarter each potato and place into a steam kettle full of water. Bring the water to a boil and cook uncovered over moderately high heat until fork tender. Drain the potatoes and put them into a stand mixer. Let them dry before lightly mashing with the whisk attachment.
Add the sour cream, butter and seasonings and mash until smooth.
In a small pan, bring the heavy cream to a simmer. With mixer on low, slowly add to the potatoes until well incorporated.
Remove from the mixer and cool completely before portioning.
Sour Cream and Scallion Sauce
Whisk ingredients together in a large mixing bowl until incorporated and smooth. Set aside until assembly.
Sandwich
On a flat-top grill, toast bread slices. Put 2 slices of Cheddar cheese on each toasted slice. Remove from heat.
Place a 5 ounce portion of the mashed potatoes on a lightly oiled flat grill and smash flat with a spatula. Cook on both sides until browned and heated through. Remove from heat.
Cut whole Idaho® Potatoes on a slicer into 1/4" planks. Blanch in hot oil.
Place 4 potato planks into the fryer basket and fry for 3 minutes until golden brown and crisp. Drain and season with salt and pepper.
Add the fried potato planks to one half of the sandwich. Place the heated mashed potato portion over the planks.
Place the bacon slices on the other half of the sandwich.
Put both halves on a cookie sheet and place under a broiler for 45 seconds or until the cheese is completely melted.
Ladle Sour Cream & Scallion Sauce over the bacon side of the sandwich. Close sandwich, sauce side up.
Hi there! I'm Dr. Potato, your AI-powered potato expert. Ask me anything about potatoes — cooking tips, storage, varieties, nutrition, and more. I'll search through hundreds of expert answers to help you out!