For pasta dough, place flour into a large bowl. Make a well in the centre, add eggs and 1-2 tbsp. iced water and using a fork whisk to combine, then stir until mixture just comes together. Remove dough and knead until smooth. Wrap in plastic wrap until required.
Divide pasta into 4, then using a pasta machine with rollers at widest setting, working with one piece at a time, feed dough through the rollers. Fold dough in half lengthways, then feed through rollers again, continuing until smooth, then reducing settings for each time, roll pasta until translucent and 1mm-thick. Dust pasta sheets with a little flour or semolina and roll then using a sharp knife cut into 2-3mm wide strips.
For pangrattato, preheat oven to 180C. In a large bowl combine ingredients and spread over an oven tray. Bake, stirring occasionally, until golden, about 10 minutes.
Place cream in the bowl of an electric mixer and whisk on high heat until it forms butter, strain through a colander and using hands squeeze out buttermilk under cold running water. Place butter into a bowl and mash through truffle and salt to taste. Cover and set aside until required.
Bring a large pot of salted water to the boil over high heat, add tajarin pasta and cook for 1-2 minutes or until al dente. Meanwhile heat butter in a large frying pan, add pasta and toss to combine. Serve pasta immediately topped with a truffled egg yolk and top with a sprinkle of pangrattato.