Coarsely chop half the pancetta. Tear remaining pancetta into pieces and set aside. Heat the butter in a 30cm (top measurement) 2L (8 cup) ovenproof frying pan over medium heat. Add onion and chopped pancetta. Cook, stirring often, for 8 minutes or until pancetta is crisp. Transfer mixture to a bowl. Rinse and dry the pan, then line with baking paper.
Meanwhile, place the cream, thyme and garlic in a small saucepan. Bring to a simmer over medium heat. Set aside to infuse until required.
Peel the potatoes and use a mandolin or sharp knife to slice to 2-3mm thick.
Preheat oven to 180C/160C fan forced. Arrange one-fifth of the potato, slightly overlapping, evenly over the base of the prepared pan. Scatter with one-quarter of the onion mixture and one-fifth of the cheese. Repeat with 3 more layers, then a final layer of potato. Top with the torn pancetta and the remaining cheese.
Strain the cream mixture over the layered potato mixture, reserving the thyme. Sprinkle with half the thyme. Cover with baking paper, then a layer of foil. Bake for 45 minutes. Remove paper and foil and bake for a further 25 minutes or until the potato is tender, pancetta is crisp and cheese is golden. Set aside for 10 minutes to firm before serving.
Serving size: 6
Recipe courtesy of taste.com.au