Procedures

1. 1

   Heat 1 teaspoon of vegetable oil in a 10- inch non stick skillet over medium high heat until shimmering. Add chopped pancetta and cook, stirring until pancetta is crisp, about 5 minutes. Add chopped shallots and cook, stirring frequently, until soft and translucent, about 5 minutes. Transfer shallots and pancetta to a large bowl using a slotted spoon. Transfer fat to a cup. Add enough oil to add up to about 4 tablespoons total fate. Set skillet aside.

2. 2

   Using the largest holes on a box grater grate potatoes one at a time. Place grated potato in the center of a clean tea towel and twist tea towel to drain out liquid over sink. Transfer to bowl with pancetta and shallots. Season to taste with salt and pepper. Add 1 1/2 teaspoons picked thyme leaves and toss to combine.

3. 3

   Wipe out skillet. Heat 1 tablespoon of fat over medium heat, and when shimmering add 1/2 of potato mixture to the skillet. Using a rubber spatula, press into the bottom of the pan and cook until edges begin to look brown, about 6 minutes. Carefully slide roesti onto a plate then place another plate on top. Flip plates over, then slide roesti back into pan and continue to cook until completely crisp, about 7 minutes longer. Transfer to a large plate and keep warm in a 200°F oven. Repeat with remaining fat and potato. Sprinkle roesti with thyme and serve with sour cream.